US drone and air strikes have killed between 64 and 116 civilians outside war zones since 2009, the White House says.

The numbers, covering the period from January 2009 to December 2015, are significantly lower than estimates by human rights groups.
Some groups say that several hundred civilians have died in US strikes.
The long-promised report was released in conjunction with an executive order to increase civilian safeguards.
President Barack Obama signed the executive order to require the government to disclose the number of civilian deaths each year in an effort to improve transparency in US military operations.
The directive, which could be cancelled by the next president, requires government reviews of air strikes to include "credible reporting" by non-governmental groups.
Human rights groups have long accused the US government of obscuring the number of civilian casualties in drone and air strikes.
The London-based Bureau of Investigative Journalism estimates between 492 and 1,100 civilians have been killed by drone strikes in Pakistan, Yemen and Somalia since 2002.
It says its figures are based on reports by local and international journalists, NGO investigators, leaked government documents, court papers and the result of field investigations.
But the Obama administration cautioned that figures from human rights groups could be flawed due to the "deliberate spread of misinformation by some actors, including terrorist organisations, in local media reports on which some non-governmental estimates rely".
The order also makes civilian protection a priority.
The assessment revealed that between 2,372 and 2,581 members of terrorist groups were killed in the 473 strikes since Mr Obama took office in 2009.
The White House declined to disclose where the civilian deaths occurred, but said the numbers excluded countries such as Afghanistan, Iraq and Syria.
The estimates do not include civilians killed during military operations when American forces are on the ground.


For the hundreds of families who took shelter from Typhoon Hagupit inside a school in Albay province, the wait is finally over.

Today they find out what state their homes and fields are in after days inside a strong building to protect them from the powerful gusts of winds and endless rain.
"I hope that our house wasn't destroyed or damaged by [the] typhoon or that it was not in the flood," says 16-year-old Ronna Mae Salturio.
Her family, one of many living in small shanties along the road, is getting ready to be taken home in a military truck with the few essentials they brought with them.
They might be worried about their future, but they have survived.
At least 21 people are known to have died during Hagupit, but that's a stark comparison with last year when more than 7,000 died or went missing from Typhoon Haiyan which left mass destruction in its wake.
There are still remote parts of Samar that are unreachable, due to floods or downed trees blocking roads, and there could be significant destruction and loss of life there.
But for the most part, the Philippines looks to have averted disaster on a national scale.
For some, it shows the government has learned its lesson and preparations were made in time.
President Benigno Aquino's administration faced much criticism for the slow response in getting food and aid to Tacloban and other areas after Haiyan.
In the Philippines, where bad weather is a part of life, Albay province is seen as a leading example of disaster management. In 1995, it set up a separate office solely to deal with emergencies and it looks to have paid off.
A total of 128,998 families were evacuated from low lying or mudslide-prone areas to schools, community centres and other stronger buildings, with the help of trucks and personnel from the military.
The governor told the BBC he went on the radio to encourage people to leave their homes and property behind.
They were also given incentives in the form of bags of rice, which for those living in poverty is a big draw.
It's all part of what the provincial government says was its strategy to minimise risk and loss of life.
"Evacuation rather than rescue, that's our doctrine," says Cedric Daep, Chief of the Albay Public Safety and Emergency Management Office.
He says they met days before the expected typhoon with local mayors to identify the major hazards. Floods, landslides, storm surges, mud flow and strong winds could destroy houses made of light materials.
Haiyan was so deadly largely because of the huge unexpected storm surges it brought with it which wiped away entire communities.
So knowing that, evacuating from low lying areas looks to have paid off.
"We are happy with the result that we achieved zero casualty," Mr Daep says.
And at the national level, food and aid distribution centres were set up early. Both the government and aid agencies were poised to act before the storm this time as opposed to reacting after.
President Aquino said before the typhoon struck that he would not be patient with excuses after this event and wanted to set a "zero casualty" target.
They also had help from the fact that Hagupit turned out to be much less destructive then predicted.
It was briefly classed as a super typhoon as it approached the Philippines, with winds of 250km/h, but by the time it hit land on Saturday it had reduced in speed significantly.
But even then, it was increased awareness of the dangers of the typhoon that made people nervous enough to leave their homes.
That fear is the legacy that Haiyan has left here.


The Australian press has expressed scorn and bewilderment over PM Tony Abbott's awarding of a knighthood to Prince Philip, the Duke of Edinburgh.

Mr Abbott announced the news that Queen Elizabeth II's husband would receive the country's top honour on 26 January - Australia's national day.
He said the Prince's life of "service and dedication" should be honoured.
But many commentators say the move raises grave questions about Mr Abbott's judgement.
They have suggested he is out of step with mainstream opinion - as well as his own party.
Mr Abbott re-introduced knighthood and damehood honours last year, nearly 20 years after they had been discontinued.
"What was the Prime Minister thinking?" asks an editorial in The Australian. "It seems his political colleagues didn't get a chance to talk him out of it."
The paper describes Prince Philip as a "symbol not just of another time but another country", who is "celebrated by Brits for his howlers and gaffes".
The editorial says Mr Abbott risks further alienating core Liberal supporters at a time when he was under fire for ignoring them.
"With the odd decision to ennoble a member of the British monarchy, Mr Abbott gives those who would lampoon him a right royal charter."
Australia's honours system
The Sydney Morning Herald shares the view of many critics that Mr Abbott is under the spell of Britain, Australia's erstwhile colonial ruler.
"It is as though he is caught in a bygone era of deference to the old country," an editorial in the paper says.
As a contrast, the paper praises the Labor opposition leader, Bill Shorten, who last weekend called for Australians to recognise that their country would be better off as a republic. Australia is a parliamentary democracy that retains Britain's monarch as its head of state.
The Herald ultimately takes a pragmatic view, arguing that Mr Abbott's actions will show the electorate his true colours.
"In one sense his blind spot on the monarchy will do Australia good in the longer term," the paper says. "It will offer voters a clear choice: to be part of a nation that evolves democratically or one that remains locked in a colonial past."
HRH The Prince Philip, Duke of Edinburgh, Earl of Merioneth and Baron Greenwich, KG (Knight of the Garter), KT (Knight of the Thistle), OM (Order of Merit), GBE (Knight Grand Cross of the Order of the British Empire), AC (Companion of the Order of Australia), QSO (Companion of The Queen's Service Order), PC (Privy Counsellor).
He also holds many foreign orders and decorations, as well as honorary appointments and ranks in the Armed Services.
Several papers stress that the knighthood may come to be seen as a tactical mis-step, weakening Mr Abbott's position as a leader. He is already under fire from party backbenchers for major policy u-turns.
"[The knighthood] gains no ground for the government and only invites ridicule," says an editorial in The Telegraph. "This government is in a position where every step must be a winning move. It has no political capital to waste."
But however damaging the knighthood proves to be, commentators say it is unlikely by itself to be Mr Abbott's downfall.
"An MP from the conservative right of the party in Mr Abbott's home state predicted it would spark fresh questioning of the Prime Minister's suitability for the job," says an editorial in The Age. "A change seems unlikely but it is the cumulative risk of errors."
A commentator in the Australian Financial Review says Mr Abbott has antagonised the opposition as well as his own base in the Liberal party by giving the award to Prince Philip.
"It is more the act of a mischievous student politician who wants to aggravate the left as part of a campus brawl," the commentator said.
"No one is talking mutiny but the prime minister needs to be careful. Liberals are averse to punting elected leaders but everyone has a breaking point."


Iain Duncan Smith's resignation was really about the EU, pensions minister Baroness Ros Altmann has said.

On Friday, Mr Duncan Smith said he was quitting as work and pensions secretary in protest at disability benefits cuts.
But Lady Altmann, who described her ex-boss as "exceptionally difficult" to work for, accused him of wanting "to do maximum damage to the party leadership" to help his campaign to leave the EU.
Sources close to Mr Duncan Smith insist his resignation was not about the EU.
Mr Duncan Smith is due to give his first interview since resigning on BBC One's Andrew Marr Show at 09:00 GMT. Stephen Crabb was appointed as Mr Duncan Smith's replacement on Saturday.
In his resignation letter, which many commentators have interpreted as an attack on Chancellor George Osborne, Mr Duncan Smith said the latest changes to benefits for the disabled were "not defensible in the way they were placed within a Budget that benefits higher earning taxpayers".
But Lady Altmann said she was "shocked" by the resignation saying her former boss had "championed the very package of reforms to disability benefits he now says is the reason he has resigned".
In a statement, Lady Altmann said: "This really seems to be about the European referendum campaign.
"He seems to want to do maximum damage to the party leadership in order to further his campaign to try to get Britain to leave the EU.
"As far as I could tell, he appeared to spend much of the last few months plotting over Europe and against the leadership of the party and it seemed to me he had been planning to find a reason to resign for a long time."
She also said she had found him "exceptionally difficult" to work for and said he had "often been obstructive to my efforts to resolve important pension policy issues".
But another of Mr Duncan Smith's junior ministers, employment minister Priti Patel, praised Mr Duncan Smith as a "great social reformer".
"Since coming to office in 2010, he has made a real difference to the life chances of people throughout the country by reforming the welfare system to ensure that work always pays," she said.
And Justice Secretary Michael Gove, writing in the Sunday Telegraph, called Mr Duncan Smith "an inspirational social reformer" who has been "guided throughout by a clear sense of noble moral purpose".
However, Mr Gove, who like Ms Patel and Mr Duncan Smith, is campaigning for the UK to leave the EU, wrote that a "united and resolute government" was needed.
He wrote that he also "hugely" admired Mr Osborne and said that "I can't - and won't - take issue with either of them in the areas they've championed and led".
In his Budget on Wednesday, Mr Osborne said the government would be spending an extra Â£1bn on the disability budget but changes to benefits announced a few days earlier had suggested the government would save Â£4.4bn on this by 2020-21.
They included changes to Personal Independence Payments (PIP), due to replace Disability Living Allowance (DLA) in January 2017, that were expected to save Â£1.3bn a year, but sparked an outcry from opposition parties and some Tory MPs.
But on Friday, before Mr Duncan Smith resigned, a government source had said the planned changes would be "kicked into the long grass".
Replying to Mr Duncan Smith on Friday, David Cameron said he was "puzzled and disappointed" that Mr Duncan Smith had decided to go when they had agreed to have a rethink about the policies.


Kenya's Deputy Prime Minister Uhuru Kenyatta has been confirmed as the winner of the presidential election, and vowed to work with his rivals.

He won 50.07% of the vote, officials said, narrowly avoiding a run-off.
But his main challenger, Raila Odinga, alleged massive fraud and said he would challenge the results of the "tainted election" in the Supreme Court.
Mr Kenyatta is set to face trial at the International Criminal Court over violence that followed the 2007 polls.
By Karen AllenBBC News, Kibera, Nairobi
Kibera slum is not normally considered friendly turf for Uhuru Kenyatta. Yet residents remained calm after the election of Kenya's richest man as their next leader. People are placing their faith in the new constitution and recent judicial reforms.
Raila Odinga is challenging the results in the Supreme Court and people say they will wait for the legal process to run its course.
Some point to the reforms as a reason for the relative calm compared with five years ago, when Kibera was a flashpoint. "Our behaviour is being shaped by the new constitution," said Steve, a Kibera resident.
But there are worries about the future. Many hope Mr Kenyatta will uphold the new constitution and continue to co-operate with the International Criminal Court, where he is fighting charges of crimes against humanity.
While the mantra across Kenya is "amani" (peace), some campaigners are warning against a "peace coma" - a failure to address past injustices which would prevent Kenya from moving on.
He is accused of fuelling the communal violence that saw more than 1,000 people killed and 600,000 forced from their homes.
After the results were announced, Mr Kenyatta told cheering supporters he would serve all Kenyans "without fear or favour".
Speaking at the Catholic University in Nairobi, he called on Mr Odinga and other leaders to "join us in moving our nation forward."
Earlier, the Independent Electoral and Boundaries Commission (IEBC) said the latest elections had been complex, but also credible and transparent.
It said the turnout, at 86%, was the largest ever
IEBC chairman Issack Hassan praised the candidates who had already conceded victory and urged others to follow suit.
However, Mr Odinga, the current prime minister, said the electoral commission had "failed Kenyans" and that democracy itself was "on trial".
But after announcing his Supreme Court challenge, he also appealed for calm, saying: "Any violence could destroy this nation forever."
Profile: Uhuru Kenyatta
The BBC's Gabriel Gatehouse in Nairobi says this was the tightest of races with the narrowest of margins.
He says that how Mr Odinga now handles his supporters will determine whether his dispute stays in the courts or spills out on the streets.
Mr Kenyatta's Jubilee Coalition party said it was "proud and honoured for the trust" bestowed on it, adding that it had taken a message to the people and that "we are grateful to the people of Kenya for accepting this message".
Early on Saturday, small groups of Kenyatta supporters celebrated in Nairobi, hooting car horns and singing.
But the newly confirmed president could face difficult relations with Western countries.
In July, he is due to go on trial at the International Criminal Court (ICC) in The Hague for alleged crimes against humanity.
Mr Kenyatta's running mate, William Ruto, also faces similar charges. Both men deny the accusations.
In his victory speech, Mr Kenyatta restated his promise to co-operate "with all nations and international institutions".
The ICC has agreed to postpone Mr Ruto's trial by a month until May after his lawyers complained of not having enough time to prepare his defence.
Countries including the US and UK have hinted that Mr Kenyatta's election as president would have consequences for their relations with Kenya. The comments have been dismissed in Nairobi as foreign interference.
A new electronic system for transmitting vote results was designed to eliminate the risk of fraud, and thus avoid a repeat of the post-poll violence of 2007.
But the count has been plagued with technical glitches, including a programming error that led to the number of rejected votes being multiplied by a factor of eight.
Mr Odinga's Cord alliance had earlier complained that votes from 11 constituencies were missing, in effect leaving him more than 250,000 votes short.


British Oscar hopeful Anna Pinnock has been given time off from new James Bond film Spectre to attend Sunday's Academy Awards - where she is nominated twice.

This year British films and talent earned 39 nominations across 19 categories at the Oscars.
Pinnock is up against herself in the production design category for Into the Woods and The Grand Budapest Hotel.
"They've given me three days off," she told the BBC at a reception in Los Angeles for British Oscar nominees.
"We're not even half-way through yet. We've just been in Italy, in Rome, then we're back at Pinewood and then it's Mexico."
Many British nominees attended the annual Great British Film Reception in Hollywood, hosted by British consul general Chris O'Connor.
Most were behind-the-camera talent from categories such as cinematography, costume design, film editing, music, sound mixing and visual effects.
Pinnock, who grew up in Canterbury, won a Bafta for her production design on The Grand Budapest Hotel two weeks ago.
Her Oscar nominations this year are her fourth and fifth in a 30-year career. Her previous nods were for her work on Gosford Park, The Golden Compass and Life of Pi.
Talking about working on Wes Anderson's quirky comedy The Grand Budapest Hotel, she said: "It appeals on every level, it's definitely his best film."
The film has nine nominations at the Oscars with Pinnock tipped to win her category.
But she's been in the same position before - being up against herself at the Baftas in 2013 for Life of Pi and Bond film Skyfall.
"I didn't win anything - so you never know," she admitted.
"I don't write any speeches, because having been onstage at the Baftas it's absolutely terrifying - it's an out of body experience. Hopefully the right thing comes out of your mouth."


Veteran Tory Ken Clarke has waded into his party's war of words with UKIP by branding them "a collection of clowns".

The pro-European cabinet minister said UKIP had no positive policies and was just "against" foreigners.
UKIP leader Nigel Farage hit back by accusing Mr Clarke of holding millions of British people "in utter contempt".
He said Mr Clarke was "obviously not interested" in winning back disaffected Tory voters at Thursday's local elections in England and Wales.
It comes as UKIP accused the Tories of conducting a "morally reprehensible" smear campaign against its local election candidates.
The anti-EU party has expanded rapidly, recruiting a record 1,732 candidates to contest Thursday's local elections.  It admits it has not had the time or money to vet all of them properly.
UKIP says it has evidence that smears about its candidates are being spread by Conservative Central Office, which it claims has been trawling would-be UKIP councillors' Twitter and Facebook pages for months.
"Were we inclined to return the favour, we would find even more examples to use against them.
"We deem that using our candidates as cannon fodder to undermine a political campaign (is) morally reprehensible and downright dirty," said a spokesman.
The party is investigating six candidates over links to the BNP and other far right groups or alleged racist and homophobic comments, following stories in national and local newspapers.
"I am glad they have found some candidates in the BNP because we don't want them. We are quite pleased. We don't want these people in the party," a UKIP spokesman said.
He said the row showed the Conservative Party was "rattled" by UKIP, which is hoping to make significant gains in Tory heartlands on Thursday, but added: "This isn't scrutiny, it's smear."
Asked on the BBC's Andrew Marr show about UKIP's claims, Transport Secretary Patrick McLaughlin said all candidates had to be scrutinised, but added: "I don't know anything about a smear campaign."
But his cabinet colleague, Ken Clarke, minister without portfolio, added fuel to the row in an interview with Sky News.
He said: "They of course have not been able to vet their candidates. Fringe right parties do tend to collect a number of waifs and strays...
"Some of them are saying quite different things now they are in politics than their actual views."
Asked whether he agreed with David Cameron's 2006 claim that UKIP was made up of "fruitcakes and closet racists", Mr Clarke replied: "I have met people who satisfy both those descriptions in UKIP.
"Indeed, some of the people who have assured me they are going to vote UKIP I would put in that category. I rather suspect they have never voted for me."
Mr Clarke said he was sure that "most of the UKIP people are perfectly nice when they are having a drink".
But he added: "The trouble with UKIP really is it is just a protest party.
"It is against the political class, it is against foreigners, it is against immigrants. But it does not have any very positive policies. They do not know what they are for."
He added: "The temptation to ordinary voters to UKIP is these are very difficult times, the political classes are regarded as having got us into a mess.
"It is very tempting to vote for a collection of clowns or indignant, angry people, who promise that somehow they will allow us to take your revenge on people who caused it."
Conservative backbencher Nadine Dorries criticised Mr Clarke's intervention, saying in a Twitter message: "I suppose Ken Clarke's strategy of being rude to and insulting Tories about to vote UKIP means we don't want them back for general election?"
UKIP leader Nigel Farage echoed Ms Dorries' comments, saying: "It is obvious that Mr Clarke holds millions of people in this country in utter contempt.
"UKIP are attracting supporters from all three main parties and, significantly those who have either not voted for over 10 years or have never voted before in their lives.
"Instead of slagging them off maybe he should try to wrap his head around the idea that UKIP are appealing to people due to the failure of the bloated self-satisfied political machine of which he is such a typical member.
"He obviously doesn't care and isn't at all interested in attracting those millions to vote for the Conservatives, well so be it. The way things are going they won't be doing so any time soon."
Lib Dem leader Nick Clegg said UKIP was a "very seductive" option for people who wanted to say "to hell with mainstream politics" but he urged voters to look at the party's policies.
UKIP has also dismissed claims in The Observer that the party's policy-making process in chaos.
The newspaper published leaked e-mails between party treasurer Stuart Wheeler and MEP Godfrey Bloom, in which Mr Bloom advises UKIP to adopt policies "off the shelf" from right-wing think tanks, because trying to reach agreement on where it stood on issues was like "herding cats".
A UKIP spokesman said: "I am glad they are discussing policies. So they should be."


A woman who killed a pensioner while "high on crystal meth and heroin" has been given a six-year sentence.

Margaret Henderson-McCarroll pleaded guilty to the manslaughter of Eddie Girvan, 67, on the grounds of diminished responsibility in May.
The 31 year old, who has 100 previous convictions, was told she must serve three years in prison.
Sentencing her, Mr Justice Treacy said it was "an horrific crime".
Speaking in court on Monday, he said the victim "must have suffered terribly".
Mr Girvan was found dead at his Greenisland home in County Antrim. He was virtually naked, bound and gagged on 18 January 2016.
He had been stabbed in the chest and suffocated after being gagged with kitchen roll and a tie to stop him calling out for help.
The court had heard previously that either injury could have killed him.
The court was told that the pair, who had known each other for some years, had argued over money for sex.
Henderson-McCarroll said she had been acting in self defence and "poked" her victim with a cake knife after Mr Girvan came at her with a stick sword.
She said she had not meant to kill him and admitted that she had been high on crystal meth and heroin at the time.
After the stabbing, Henderson-McCarroll admitted taking more heroin "to calm her nerves" before stealing Mr Girvan's car and driving it to Belfast.
She was involved in an accident at Custom House Square, Belfast which led police to find Mr Girvan's car at the city hostel where she had been living.
She was later arrested on an unrelated bench warrant and found to have a sat nav, a watch, and two sets of car keys in her possession.
The sat nav contained Mr Girvan's home address and, after several attempts to contact him at home, police broke in and found his body.
Henderson-McCarroll has 100 previous convictions for robbery, theft and assault.
The court heard she had bitten, punched and head butted elderly men, young women and children in the course of past crimes.
A doctor's report stated that she had lived a "chaotic life" of drug addiction, alcohol abuse, crime and prostitution.
The court was told that she relapsed into heroin and crystal meth addiction after the death of her baby daughter.
She also previously admitted eight other charges connected to Mr Girvan's killing:
* Theft;
* Attempted theft;
* Aggravated vehicle-taking causing damage;
* Dangerous driving;
* Driving when unfit through drink or drugs;
* Driving without insurance;
* Failing to stop at an accident
* Failing to report an accident
For those crimes, she was sentenced to between one month and a year in prison - all to be served concurrently with her manslaughter sentence which was six years - three to be served in prison and three on licence.


Austria's ruling coalition has agreed to prohibit full-face veils in public spaces such as courts and schools.

It is also considering a more general ban on state employees wearing the headscarf and other religious symbols.
The measures are seen as an attempt to counter the rise of the far-right Freedom Party, whose candidate narrowly lost last month's presidential vote.
The centrist coalition nearly collapsed last week amid crisis negotiations over the government's future direction.
Detailing the package of reforms, the coalition devoted just two lines to the planned ban on the Islamic niqab and burqa.
"We are committed to an open society, which also presupposes open communication. A full-face veil in public places stands in its way and will therefore be banned," it said.
An estimated 150 women wear the full niqab in Austria but tourism officials have expressed fears that the measures will also deter visitors from the Gulf.
One government spokesman told an Austrian newspaper that the ban would apply for ski resorts such as Zell am See as much as the centre of Vienna.
Several European countries have imposed similar bans but the Austrian move is, according to the vice chancellor a "symbolic" step.
Integration Minister Sebastian Kurz said it was important to be seen to be neutral, especially for anyone dealing with the public in the police or schools.
France and Belgium introduced a burqa ban in 2011 and a similar measure is currently going through the Dutch parliament.
Chancellor Angela Merkel said last month that the full-face veil should be prohibited in Germany "wherever it is legally possible". The UK does not ban the niqab or burqa.
Further measures agreed by Austria's Social Democrats and their conservative People's party partners include electronic tagging of former jihadists and a proposed curb on foreign workers.
Many of the plans must be hammered out in detail and receive parliamentary approval before they can come into force, BBC Vienna correspondent Bethany Bell reports.
The niqab is a veil for the face that leaves the area around the eyes clear. However, it may be worn with a separate eye veil. It is worn with an accompanying headscarf.
The burka is the most concealing of all Islamic veils. It is a one-piece veil that covers the face and body, often leaving just a mesh screen to see through.


Star Wars: The Force Awakens will be hitting the big screens soon.

10 December 2015 Last updated at 16:58 GMT
The film will see the return of aliens, droids and many other weird and wonderful creatures.
The man who created them, Neal Scanlon, showed Newsround his top three creatures.


Prime Minister Theresa May has told MPs: "We will never waver in the face of terrorism."

Paying tribute to Pc Keith Palmer, who died after being stabbed, she said: "He was every inch a hero and his actions will never be forgotten."
Delivering a Commons statement she said Wednesday's attacker was British born and known to police and MI5. The attack was related to "Islamist ideology".
Labour leader Jeremy Corbyn described the attack as "an appalling atrocity".
Four people died, including the attacker, with 40 more injured.
Mrs May said the victims included 12 Britons, three French children, two people from Romania, four from South Korea, one from Germany, one from Poland, one from Ireland, one from China, one from Italy, one from the US and two Greek people.
She told MPs: "Yesterday an act of terrorism tried to silence our democracy, but today we meet as normal, as generations have done before us and as future generations will continue to do, to deliver a simple message: We are not afraid and our resolve will never waver in the face of terrorism."
She said it was still believed that the attacker acted alone and there was "no reason to believe" further attacks on the public were planned.
"His identity is known to the police and MI5 and when operational considerations allow, he will be publicly identified," she said.
"What I can confirm is that the man was British-born and that some years ago he was once investigated by MI5 in relation to concerns about violent extremism.
"He was a peripheral figure. The case is historic. He was not part of the current intelligence picture. There was no prior intelligence of his intent or of the plot."
Describing it as an attack on free people all over the world, Mrs May thanked global allies including US President Donald Trump for their support.
"We meet here in the oldest of all parliaments because we know that democracy and the values it entails will always prevail," she said.
"Those values - free speech, liberty, human rights, and the rule of law - are embodied here in this place but they are shared by free people around the world.
"A terrorist came to the place where people of all nationalities and cultures gather to celebrate what it means to be free. And he took out his rage indiscriminately against innocent men, women and children.
"This was an attack on free people everywhere - and on behalf of the British people, I would like to thank our friends and allies around the world who have made it clear that they stand with us at this time."
Mrs May also paid tribute to Foreign Office minister Tobias Ellwood, who tried to save the life of PC Palmer by giving him mouth-to-mouth resuscitation and attempting to stem the flow of blood from his stab wounds in New Palace Yard.
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And she praised the police for "heroically" doing their job by stopping the attacker getting access to Parliamentary buildings by shooting him dead "within 20 yards of the gate".
"If his intention was to gain access to this building, we should be clear that he did not succeed," she said.
She also said it was wrong to describe the attack as Islamic, claiming it was "Islamist terrorism - it's a perversion of a great faith".
Mr Corbyn said MPs were "united by our humanity, by our democratic values and by that human impulse for solidarity to stand together in times of darkness and adversity".
"I express my condolences to the family and friends of PC Keith Palmer, who gave his life yesterday in defence of the public and our democracy - and to the loved ones of those still in a critical condition, including the French schoolchildren visiting our capital from Concarneau in Brittany," he said.
"The injured include people of ten nationalities. Innocent people were killed yesterday walking across Westminster Bridge as many millions of Londoners and tourists have done before them."
Conservative MP James Cleverly fought back tears as he paid tribute to his friend PC Palmer, who he met 25 years ago in the Royal Artillery. He asked Mrs May whether the police officer's "gallantry and sacrifice" could be recognised posthumously - to which she replied, that this would be considered in due course.
SNP Westminster leader Angus Robertson said: "Today of all days we are reminded, notwithstanding our differences on political and constitutional issues, we are as one in our dedication to democracy, rule of law and harmony between people of all faiths and none."
He wished Mrs May and Home Secretary Amber Rudd well in their work in the aftermath of the "appalling, indiscriminate, terrorist act".
Liberal Democrat leader Tim Farron said MPs were "beyond thankful to the police, to the NHS, to the emergency services, actually to the staff of this House, in keeping us safe and being so utterly dedicated to their roles".
He said: "Those who attack us hate our freedom, our peaceful democracy, our love of country, our tolerance, our openness and our unity."
Nigel Dodds, deputy leader of the Democratic Unionist Party, said PC Palmer "and his colleagues are the reason that we're here today and every other day".
Over in the House of Lords, the Archbishop of Canterbury said: "Yesterday afternoon, one of our own security staff at Lambeth Palace - a Muslim - arrived at the gate having been missed by the vehicle very narrowly, and spent time helping those who'd been injured.
"It was typical of this community in this country that he refused to go home until the end of his shift, and simply spent the time doing his job as he expected."
But outside Parliament, UKIP leader Paul Nuttall called on the Muslim community to help cut out the "cancer within our society of radical Islam".
He said security needed to be heightened, adding that "all that was needed for this terrorist attack to take place yesterday was a Hyundai 4x4 and a couple of kitchen knives".
Earlier MPs, peers, police and workers around Whitehall observed a one minute's silence.
Commons deputy speaker Lindsay Hoyle said Parliament's security committee will hold an emergency meeting later on Thursday to discuss security arrangements on the estate.
Speaking beside a police cordon outside Parliament, Mr Hoyle told BBC Breakfast: "We're in a village and our village policeman has been murdered and all of our thoughts are with the family and the other innocent victims.
"But of course the House must continue -  we will not give in to terrorism and today we'll continue.
Mr Hoyle, who is also chairman of the security committee, said: "We will be having an emergency meeting. We'll be getting information - what else needs to be put in place - and we will reflect."
He said there would be support for MPs and staff who "witnessed things they never expected to witness in their lives", he said.
Mrs May has spoken to Mr Trump, German Chancellor Angela Merkel, French President Francois Hollande and Romanian President Klaus Iohannis in the period since the attack, and will speak to more foreign leaders over the course of Thursday, Downing Street said.
The PM's official spokesman said Mrs May had been "focused entirely on this issue since it happened" and was in constant contact with police and security services.
He declined to discuss whether any changes had been made to her schedule for the coming days.


A man has been arrested on suspicion of murder after a body was found in Bristol on Sunday evening.

The male victim was found with serious head injuries at a property in Hungerford Road, Brislington, shortly before 20:00 BST.
Avon and Somerset Police said the man was pronounced dead at the scene.
The 38-year-old suspect remains in police custody. Hungerford Road is expected to remain closed until Monday evening while investigations continue.


The threat from terrorism is always evolving, but some things remain constant - the emotions of loss and the risks taken by those who want peace, writes Peter Taylor.
When I first started working in television 50 years ago, I never imagined that I would spend much of the next half century reporting the phenomenon of terrorism.
From those early days I have tried to understand the roots of violence and explain not what happens but why it happens.
Gradually I got used to reporting death. But I never became insensitive to it.
During Northern Ireland's Troubles, I got to know a loyalist assassin - Billy Giles - well and grew to like him. I first met him when making a documentary in the Maze Prison in 1989.
I talked to Billy in his cell. He was doing life for the murder of his Catholic workmate. He had lured him into a car and then shot him in the back of the head.
"The only way to stop them was to terrorise them. It was them and us," he said. But the act of pulling the trigger had a profound effect on Billy.
"Before I was a decent young man. It [the conflict] turned me into a killer. It felt like someone had reached down and ripped my insides out. You hear a bang and it's too late. [I] never felt a whole person again."
He was released under the Good Friday Agreement - which established peace in Northern Ireland - and I met him again. He was a man transformed from the gaunt, haunted figure I'd met in the Maze. He was now wearing a suit, collar and tie and carrying a briefcase.
He looked every inch a businessman and not a loyalist killer. Billy was upbeat and optimistic as he told me about starting a new life. But his ambition proved illusory.
I later heard that he'd hanged himself. I was shattered. I couldn't believe that he'd taken his own life. He left a suicide note. He said he'd ordered a Chinese takeaway, prepared the noose and sat down to write a letter.
"I was a victim too, now hopefully I'll be the last. Please don't let any kid suffer the history I have. Please let our next generation live normal lives. Steer them towards a life that is Troubles free. I've decided to bring this to an end now. I'm tired."
I remember reading Billy's suicide note, hoping that his final wish would come true. At least some of it has.
The emotion that has never left me is the profound sadness I feel for some of those whom I have met, got to know and interviewed. One interview affected me personally above all others.
The blanket protest by the IRA prisoners in the Maze started in 1977. They refused to wear prison uniform, insisting they were political prisoners and not criminals. The protesters resorted to wearing only a blanket to try and force the issue.
To try and understand the situation from the other side of the cell doors, I met Desmond Irvine, the secretary of the Northern Ireland Prison Officers Association.
As a unionist prison officer, what he said came as a surprise. He agreed to do an interview despite the Northern Ireland Office advising him against it. I felt he wanted to get his message across.
I asked if he respected the prisoners for their protest. "I don't think they just do it mainly for publicity but because it's their belief. I suppose one could say a person who believes sincerely in what he is doing, and is prepared to suffer for it, [deserves] a certain measure of respect which you give to him."
After transmission, he wrote me a letter saying how pleased he was with the positive reaction he had had to the interview.
Then a few days later, the IRA shot him dead.
Deeply shocked, I felt sick. At his funeral I cried. And I remember the prison governor telling me not to blame myself, saying he was murdered because he was a prison officer and not because I had interviewed him.
But I'm still haunted by what happened. I was called by a Belfast journalist who asked how it felt to have blood on my hands. Death had come too close to home and I seriously considered stopping reporting Northern Ireland. In the end, I decided to carry on.
Peter Taylor's documentary, Fifty Years Behind the Headlines - Reflections on Terror, is on Saturday 1 April at 20:00 BST on BBC Radio Four.
The pain I felt was nothing compared with that suffered by loved ones long after victims are forgotten.
Joan Wilson was one of the most unforgettable people I met. She lost her 20-year-old daughter, Marie, a nurse, in the IRA bomb attack on Enniskillen's Remembrance Day parade in November 1987.
Eleven people died, all of them Protestants, and all civilians, apart from one police reservist. Over 60 were injured.
Joan was at home when the bomb went off. "I thought, well, Gordon [her husband] and Marie are there. I hope nothing terrible has happened."
Both were buried under 6ft of rubble. Gordon managed to reach Marie's hand. "Daddy, I love you very much," were the last words she uttered.
Joan rushed to the hospital knowing little of what had happened. "I was absolutely horrified to see Marie on the bed, wired up. I took her hand, and it was cold. "As we stood there watching her life ebbing away, it ebbed away, and she passed over to our heavenly father in our presence."
The attack did incalculable damage to the IRA and the beginning of the peace process can be traced from that day.
At the time, British and Irish intelligence services believed that Martin McGuinness was the acting head of the IRA's Northern Command - in whose operational area the attack took place - although when I put it to him, he denied it.
I interviewed Joan after McGuinness had become Ian Paisley's partner in the Stormont government's devolved power sharing executive - a sight you might think Joan would find hard to stomach. But that wasn't the case.
"I'm very pleased to see Dr Paisley, whom I regard as a great man of God, sharing with Martin McGuinness, and I think each will be good for the other.
I've spoken to many victims of the IRA's campaign and many, like Lord Tebbit, whose wife Margaret was paralysed in the Brighton bomb, would profoundly disagree.
Tebbit is excoriating in his condemnation of Martin McGuinness and furious at the media hagiography that he believes followed McGuinness's death.
Peace eventually came to Northern Ireland, but other conflicts have proved more intractable.
Going through my archive of over 100 documentaries reminds me of how chillingly prophetic many interviewees have been.
In Lebanon, 25 years ago, I talked to Col Bill Cowan, the US undercover soldier sent to identify the masterminds behind two devastating truck bomb attacks carried out by Islamist suicide bombers in Beirut in 1983.
The first reduced the US Embassy to rubble, killing 63 people including most of the CIA station. Six months later, the second suicide bomber killed 241 US Marines at their base south of Beirut. Many perished in an avalanche of concrete and masonry.
I later interviewed Cowan by one of the few walls left standing - it had been part of a bar and you could still see a Playboy bunny drawn on it. He warned: "Unless we find a way of working with Islamic fundamentalism, we are going to face much, much greater threats over the next decade."
The threats went far beyond the next decade. In 1998, al-Qaeda suicide truck bombs shattered two of America's east African embassies, massacring more than 200 people, most of them Muslims.
Then three years later, 9/11 claimed the lives of almost 3,000 - it was a dramatic wake-up call to the world that Cowan's dire warning had come true.
In another interview shortly after 9/11, Dewey Claridge, the spy who helped set up the CIA's Counterterrorism Centre, described what he wanted to see happening to Osama Bin Laden.
"I don't want him brought to trial. I don't want to see a dead body because that just makes him a martyr. I just want him to disappear. Concrete shoes dropped into the Indian Ocean takes care of the dead part of 'dead or alive'."
Bin Laden's fate was exactly as Dewey Claridge's crystal ball had predicted.
In Northern Ireland it was a military stalemate that persuaded the British and the IRA to talk.
That stalemate, in which the SAS and its covert intelligence arm, known as the "Det" (for Detachment), left the IRA in no doubt that the "Brits" were not going to allow the IRA to win.
Between 1983 and 1992 the SAS and the Det shot dead 35 IRA suspects.
I remember doing an interview with one "Det" operator, a young woman, who described the celebrations back at base after the killing of IRA volunteer, William Price in 1984. To some of the team, the permanent removal of an IRA man from the battlefield was cause for a party.
"They [the IRA] make no secret of the fact that they celebrate the death of a soldier or policeman," she told me. "We celebrated in the same way. If a terrorist was shot, there was a cake made with their name on it."
Wasn't that macabre? "Possibly," she replied, "but the saying is live by the sword and die by the sword."
I finally found a photo of the cake - in the shape of a cross, with icing round the edges and "RIP" etched above the place where Price was killed.
Perhaps the most uplifting stories in the midst of seemingly endless atrocities are about those who have the courage to take great personal risks to work towards peace.
I found that the Derry businessman, Brendan Duddy, displayed extraordinary generosity of spirit. For over 20 years, he was the vital secret back channel intermediary between the MI6 officer Michael Oatley (and later his MI5 successor) and the IRA's ruling Army Council, via Martin McGuinness.
This top secret channel of communication cultivated for so long in the shadows ultimately led to the IRA ceasefire and the Good Friday Agreement.
It took me many months to discover the identity of the mysterious intermediary and when I finally did, to my astonishment, his first words were: "I've been waiting to hear from you."
A long night followed at Duddy's home, in the tiny parlour where many of the secret meetings were held. He told me his remarkable story.
Extraordinarily, IRA leaders were being smuggled over the border and brought in from Belfast for negotiations with the British government via MI6 and MI5.
It was 10 years after our first contact before Brendan finally agreed to an interview.
The emotional stress he had suffered in his efforts to bring peace were apparent in his voice.
He described being present at the seminal first meeting in his parlour between the MI6 officer, Michael Oatley, and Martin McGuinness in 1991.
I asked why he had taken the risks he had. "When you ask questions like that I choke. I get emotional. I find it hard to answer. I had no choice."
But can the principle of engaging with the enemy be applied to other conflicts?
The former director of MI5, Eliza Manningham Buller, believes that it can. I interviewed her when the main threat came from al-Qaeda, in the wake of the 7/7 London bombings.
The so-called Islamic State was yet to emerge. I asked if the "war on terror" was winnable. "Not in the military sense," she said.
"There won't be a Waterloo or an El Alamein. The terminology about winning the 'war on terror' was not something that I ever subscribed to. It's always better to talk to the people who are attacking you than attacking them. I would hope that people are trying to reach out to the Taliban, to people on the edges of al-Qaeda to talk to them."
So after 50 years what are the lessons to be learned about defeating terrorism?
It has to be tackled on both the military and political front, with both security forces and their political masters being sensitive to the delicate balance between alienating communities and gaining their support.
In the absence of the elusive military victory, governments also need to be ready to engage with the enemy as the British did with the IRA, the Spanish have tried with Eta and most recently the Colombians have achieved with the Farc.
All these were possible because the enemy had a political agenda around which there could be dialogue.
The problem with al-Qaeda and the so-called Islamic State is that their agenda embraces a thousand years not 50. And al-Qaeda and IS are infinitely more ruthless and indiscriminate than the IRA ever was.
It is even difficult, as last week's attack in Westminster shows, to establish whether or not an attacker is genuinely one of their adherents or supporters.
Although victory over IS may be declared in Mosul and Raqqa, the final victory lies not in crushing its armies on the battlefield but in defeating its ideology.


A doctor has been jailed for 15 months after being found guilty of carrying out attacks against his family.

Michael Lever, 43, strangled Caroline Lever at hospital accommodation at Law Hospital, Carluke, while she was pregnant between 1997 and July 1998.
He was also convicted of attacking her son between July 2001 and March 2004 and his 16-year-old daughter between January 2008 and January 2010.
Glasgow Sheriff Court heard the General Medical Council had been informed.
Mrs Lever, 42, told the court Lever moved in to the flat she shared with her son, Patrick George, at Dowanhill Street, Glasgow, within months of them becoming a couple.
She recalled the time when he attacked her after they moved to hospital accommodation at Law Hospital.
The witness confirmed Lever knew she was pregnant and she had no memory of how the incident began.
Mrs Lever told the jury: "He strangled me over a table."
In his evidence Mr George described how he recalled Lever strangling his mother.
He told the court: "I was scared that he was going to kill her."
The court also heard of an incident when Lever held a knife to his own throat during an argument with his wife and threatened to kill himself.
The incident, which took place at Sydenham Road, Glasgow, was also seen by Mr George and his mother, who were said to be scared.
The court heard that when the family lived in Denholm in the Scottish borders, Lever slapped Mr George on the side of the face for taking one of his university books with him to school.
Sophie Lever, 16, also gave evidence against her father and told how she was hit by a can of beer after an argument.
She told the jury that the family were living in Marchmont Terrace, Glasgow, when the assault happened.
Lever, from Nether Auchendrane, Ayr, denied the charges but was found guilty by a jury at Glasgow Sheriff Court.


A 13-year-old girl was among three people found guilty of a "brutal" race hate attack on two Muslim women.

Paul Anderson, 37, Joanna Farrer, 38, and the girl were convicted at Woolwich Crown Court on Tuesday of religiously aggravated actual bodily harm.
The victims, a mother and daughter, were punched and kicked repeatedly during the attack in Eltham last May.
Anderson, of Sevenoaks, was jailed for three years. Farrer, of Eltham, and the girl will be sentenced at a later date.
The court heard the attack, on 5 May, started when the younger victim had an altercation with the teenager, then aged 12, as she and a boy crossed Middle Park Avenue in Eltham, south east London, in front of her car.
It escalated when the daughter, a 23 year old, met up with her 42-year-old mother and they bumped into the girl and the boy again, who verbally abused the mother.
The girl - who cannot be named because of her age - then attacked the daughter before running off as the woman backed away to call the police.
But she quickly returned with Anderson, Farrer and another, unidentified, woman, the Met Police said.
Anderson punched the 42-year-old woman to the ground whereby one of the female attackers tried to rip off her hijab.
He then punched the younger victim and both women were repeatedly struck by the gang as they lay on the ground, police said.
The attack only stopped when one of the victims managed to flag down a passing ambulance, causing the suspects to flee.
In sentencing, Anderson was ordered to pay Â£2,000 in compensation to the victims and had an extra month added to his sentence after he called the victims and members of the jury "an offensive word" during the trial.
Farrer will be sentenced on 21 April while the girl will be sentenced at Bromley Youth Court on a date to be set.
Melanie Pressley, of the Met Police's Greenwich Community Safety Unit, said: "This was a brutal and completely unnecessary attack on two Muslim women who were racially abused and then assaulted.
"The victims were left terrified by what happened and lived in fear they would be targeted again."


Barrow defender Shaun Beeley says his move into non-league was a 'no-brainer' as the club set their sights on promotion to the Football League.

Beeley, 27, turned down a new deal with League Two Morecambe at the end of last season to join the fifth-tier side.
The full-back, who made 93 League appearances for the Shrimps over a two-year spell, accepted the Bluebirds' offer straight away.
"In my eyes it's definitely a move forward," Beeley told BBC Cumbria.
"The gaffer Paul [Cox] was interested, it was a bit of a no-brainer for me."
He continued: "Barrow are a team that will be going for it, they want to achieve promotion.
"The quality of the lads that we've got and the manager himself, I don't see why we can't push for promotion this year."


Nico Rosberg headed team-mate Lewis Hamilton as Mercedes dominated first practice at the Italian Grand Prix.

The German was 0.203 seconds quicker than Hamilton, with Ferrari's Kimi Raikkonen third, a second off the pace.
Mercedes set their times on the super-soft tyre, while Ferrari used the soft, which would account for about half the gap between the two cars.
Ferrari's Sebastian Vettel was fourth, ahead of Force India's Sergio Perez.
Hamilton enters the race nine points ahead of Rosberg in the championship after recovering from 21st on the grid to finish third at the Belgian Grand Prix last weekend, as Rosberg won.
Ferrari have used the last of their remaining engine development 'tokens' ahead of their home race in an attempt to boost their competitiveness after a slump in form that has seen them lose second place in the constructors' championship to Red Bull.
The fastest Red Bull was Max Verstappen in eighth, behind Haas driver Romain Grosjean and Williams' Valtteri Bottas, whose team-mate Felipe Massa announced on Thursday that he would retire at the end of the year.
Verstappen remains the focus of attention following his controversial battle with Raikkonen in Belgium.
Raikkonen has criticised Verstappen for being too dangerous, while the Dutchman said he would not change his driving because others were not happy.
The stewards took no action against Verstappen in Spa, but BBC Sport has learned that Charlie Whiting, the F1 director of governing body the FIA, felt that Verstappen's late move in defence at 200mph as Raikkonen attacked was on the edge of acceptability.
Whiting told the teams in a meeting on Thursday that he felt Verstappen could have received a black-and-white warning flag for his driving.
The black-and-white flag is an indication of unsportsmanlike behaviour and is only shown once. If the driver commits the same offence again he can be disqualified from the race.
Whiting's intervention raised the stakes in the debate ahead of the drivers' briefing after practice on Friday afternoon, where the incident is expected to be discussed.
It was a relatively low-key session on track, despite a number of drivers running off the track at the tricky Monza chicanes in the warm sunshine.
McLaren's session came to an unfortunate end as Fernando Alonso was forced to pit with a gearshift problem. He was 13th, with team-mate Jenson Button 11th, the drivers expecting their most difficult weekend of the year because of the lack of power of the Honda engine, which still lags despite recent updates.
Button and Verstappen ran the halo head protection system in the first part of the session as trials continue ahead of the planned introduction of the device in 2018.
Italian Grand Prix first practice results
Italian Grand Prix coverage details


A molecule which may control how acupuncture relieves pain has been pinpointed by US researchers.

Experiments in mice showed that levels of adenosine - a natural painkiller - increased in tissues near acupuncture sites.
The Nature Neuroscience study also found that in mice resistant to the effects of adenosine, acupuncture had no effect.
Pain experts said the findings may partly explain how the treatment works.
Adenosine is known to have many roles in the body including regulating sleep and reducing inflammation, the researchers said.
Other research has shown that it becomes active in the skin after an injury to act as a local painkiller.
In the latest study, the researchers were looking at the effects of the molecule in the deeper tissues which acupuncturists target with fine needles.
The team performed a 30-minute acupuncture session at a pressure point in the knee of mice that had discomfort in one paw.
They found that in mice with normal functioning levels of adenosine, acupuncture reduced soreness by two-thirds, as assessed by nerve sensitivity measurements.
In mice specially engineered to lack the receptor for adenosine, acupuncture had no effect.
And during and immediately after an acupuncture treatment, the level of adenosine in the tissues near the needles was 24 times greater than before the treatment, the researchers said.
Then using a drug which extends the effects of adenosine, they found that the benefits of acupuncture lasted three times as long.
Study leader Dr Maiken Nedergaard, a neuroscientist at the University of Rochester Medical Center, said: "Acupuncture has been a mainstay of medical treatment in certain parts of the world for 4,000 years, but because it has not been understood completely, many people have remained skeptical.
"In this work, we provide information about one physical mechanism through which acupuncture reduces pain in the body," she added.
Acupuncture is used for a wide range of treatments but on the NHS its use is limited to lower back pain.
Experts pointed out that acupuncture may mediate its effects in a number of different ways.
A spokesman from the British Pain Society said: "We have known for a long time that acupuncture alters the response to pain by modulation of some of the pain pathways in the spinal cord, and also by the release of endorphins.
"It is very interesting that scientists have found an alteration in the tissue levels of adenosine, which helps to explain some of the modulatory effects of acupuncture on pain perception."
Professor Edzard Ernst, professor of complementary medicine at Peninsula Medical School agreed the study might go some way towards explaining how acupuncture reduces pain.
"We need, I would argue, independent replications with more rigorous controls before we can fully accept its findings.
"The curious thing with acupuncture is that we seem to understand better and better how it might work and, at the same time, we have more and more reason to doubt that it works."


Chancellor Philip Hammond will update MPs on the government's taxation and spending plans during the Autumn Statement on Wednesday.

It will be the chancellor's first opportunity to outline his priorities in the wake of the Brexit vote.
BBC Wales spoke to a mother-of-three who hopes Mr Hammond will give reassurances to families like hers about the impact on the economy of leaving the European Union.
In the uncertain financial and political climate Cathryn Scott, who lives with her husband Jonathan Hurley in the Heath area of Cardiff, has concerns about her young family's future.
The 38-year-old, who writes a blog for mums living in Cardiff, is one of 201,200 self-employed workers in Wales.
"I do worry about the future, we had three children quite close together all within four years, so we could have three children all at university at the same time," she says.
"They could still be at home until they are in their mid 20s."
Prices are rising in the UK at the steepest rate since 2011, with uncertainty over Brexit weakening the pound and driving up the cost of materials.
"I feel like we were just coming out of a recession and we are going to go back into it," says Cathryn, who left her job in 2007 to become a freelance journalist.
With three children, two-year-old Isaac, Eva, six, and five-year-old Owen, the family feel lucky, but she says they have had to cut back on luxuries and change their spending habits.
On Wednesday in his first Autumn Statement, Mr Hammond is expected to promise help for the group described as JAMs, the households "just about managing" to avoid poverty - a group Theresa May made a priority to help in her first speech as Prime Minister.
According to the Resolution Foundation independent think tank, 35% of working age households in Wales are JAMS. These are families who have at least one person in work, they can earn up to £50,000 but are struggling to cope because of several children.
"It is when we get unexpected expenses that it's a nightmare," said Cathryn, adding that the children had never been abroad, but had instead enjoyed holidays in a caravan borrowed from a friend.
"We had a few things in one month; the car wouldn't work, my toddler broke the TV, and then I crashed the car into a bollard - which was my fault, but it all added up to about £2,000."
Cathryn and her family have invited BBC Radio Wales' Good Morning Wales programme to talk about the economy over breakfast ahead of the Autumn Statement.
While record levels of people are now in work in both the UK and Wales, many of the jobs are low paid and low skilled.
As of April 2016, 1,421,700 people were in employment in Wales, earning an average (median) wage of £492 a week, or £25,584 per annum.
Historically, Wales has recorded the lowest wages in the UK, but in April this year the East Midlands' average (median) came in at £9 lower, according to labour market statistics by the ONS.
Over 350,000 people are classed as part-time workers - making up 26% of the workforce in Wales.
Cathryn said her decision to scale back since she left full time work had made an impact on her day-to-day decisions and she felt like the 'middle' were being squeezed.
"A lot of the mums I know have to work and find that a lot of the money they earn goes on childcare," she said.
"We would like to redecorate our house, but we just don't have that kind of money at the moment, and if we did we would worry about spending it."
She is always on the look out for a bargain, cooks in batches, saves up points, and shops at a discount supermarket chain because it is cheaper - her Christmas shopping is done months in advance to take advantage of the sales.
"I think, will I ever be able to afford to retire? And being self employed, there is no company putting into my pension," she adds, saying the cost of petrol and heating added to the problem.
With Wales having the highest proportion of people living in relative poverty - 23%  - in the UK outside London, and the highest percentage of children living in poverty - one in three - of any nation in the UK, Cathryn feels her family are lucky and worries about the impact of potential cuts on people worse off than her.
"It feels like the rich get rich and the poor are getting poorer," said Cathryn.
"I worry more about other people, I'm concerned about people having their benefits cut.
"We live in the 21st Century and in Wales we have some of the worst child poverty levels. We need some reassurance that people aren't going to be worse off."
The couple has already set up a savings account for their children to send them to university, but Cathryn worries about their future financial security. She also worries about the state of public services including the NHS.
While there have been some spoilers, it will not be clear exactly what will be in the Autumn Statement or what the impact will be for public services and infrastructure in Wales until Mr Hammond gets to his feet in the Commons on Wednesday afternoon - and then Cathryn, and families like hers, will see if any changes affect their pockets.


Police in Austria are hunting for at least six men accused of "unprecedented" sexual assaults on New Year's Eve in the city of Innsbruck.

The men, described as Asian or north African, surrounded 18 women watching a firework display, kissing and groping them, police said.
A special police investigation team is conducting the search.
Authorities said they were also searching refugee shelters for the suspects.
The attack happened in the city's main square, where thousands had gathered for the New Year's Eve celebration, the AFP news agency reported.
The head of the investigation, Ernst Kranebitter, told the BBC that the scale of the attacks and the way they were carried out were unprecedented for Innsbruck.
Innsbruck's attacks come a year after more than 100 women reported sexual assaults in Cologne, Germany, on New Year's Eve 2015. Gangs of migrants were accused of the assaults.
Cologne responded with an increased police presence at this year's event. But police were accused of racial profiling, and it emerged that almost all of the 650 people stopped for identity checks were north African.
Meanwhile, reports of mass sexual assaults in the southern Indian city of Bangalore on New Year's Eve have been dismissed by local police.


We may know by the weekend if the Empress of Europe will be dethroned sooner rather than later, or if her latest deal on the refugee crisis will save her bacon.

Either way it raises profound questions about the purpose and direction of the European Union (EU).
The regional elections in Germany will be a good indication if Angela Merkel's plunging popularity among German voters has really been halted.
If it hasn't, Mrs Merkel's party may not let her stand in the next general election.
Mrs Merkel, or Anjela Myrtle as one vox populi had it on the World This Weekend, has long seemed a straightforward politician, shorn of both drama and charisma. But she is growing increasingly enigmatic, baffling even close observers.
The new deal with Turkey is her deal, more than the European Union's - the FT says it was done behind the back of her European allies, and left some of them "bruised and angered" by cutting them out in a "brutal" manner.
Migrant crisis: EU and Turkey plan one-in, one-out deal
Migrant crisis: Will Merkel be left out in the cold?
Greece needs EU help to avoid chaos, says Merkel
Profile: Angela Merkel
Even the famously myopic British media now report what Mrs Merkel says as a matter of some note.
This partly reflects the fact she has been around for ten years, longer than any other European leader.
But there is another reason, which goes to the forgotten heart of the debate about the European Union.
Who is boss? Who is in charge? Whose word counts? And how to deal with the obvious, the natural answer to those questions ever since the unification of Germany in 1871.
We don't talk about it, but it matters more than most of the froth and flotsam about this debate.
It is both right and proper that in this country the debate about EU membership is about our prosperity, security and without being too pompous, our destiny.
But in or out of the EU will not change the fact that the UK will continue to exist on the edge of a large continent with which we have long had a mingled history of occasional splendid isolation and equally irritated engagement.
When absorbed in the European question the British aim has usually been balance - to make sure no one other power has sway.
Given the potential for misinterpretation and misunderstanding I want to state explicitly that making this point is not an argument for or against continued participation in the EU - it is however an argument that we are likely to continue to be vitally engaged with the rest of Europe whether or not we are part of this particular organisation.
You can believe the origins of the European Union were a desire for a country called Europe or a project about creating a super power to rival the US and you will have a point.
But the last part of the aphorism of NATO's first secretary general Lord Ismay about that organization is more apposite: "To keep the Americans in, the Russians out, and the Germans down."
The European coal and steel community, the forerunner of the European Economic Community, was founded explicitly to create a common market in the materials of war, and to keep them out of Germany's hands alone.
This may seem like ancient history - Germany is clearly not going to wage war on the rest of Europe, it is one of the least aggressive nations in the world and any danger has long past.
In one sense that is all true. It might be that German dominance of Europe is rather better for the continent than, say, if the French or Italians were in such a role.
But the problem, or at least fact, of German pre-eminence has a new and ever-building relevance.
Since reunification Germany is once again the richest and most powerful country in Europe.
Guilt over the war will take a long time to fade, and will perhaps always make the country more thoughtful about conflict than others.
But there is an ever-growing assertiveness, and more and more Germans now believe that putting the national interest before the interests of the continent as a whole is no longer sinful and unspeakable.
It was a telling moment when Angela Merkel was first elected that she felt free to tour a submarine, like any other leader of a major power would. It didn't summon up ghosts of the past.
But wind forward a few years and that didn't stop the Greeks putting cartoons of her portrayed as Hitler on their banners when protesting against austerity measures.
German power is at the heart of the two crises facing Europe. Angela Merkel is not to blame for the Syrian civil war or the lure of Europe as an economic destination.
But she did make it clear Syrian refugees were welcome, a move that is still puzzling the best-informed commentators.
She has insisted that other countries should do more, and that the passport-less, border-free area of Schengen should not be a victim of her call.
At the heart of the Greek Euro crisis is the view held by many influential people in Germany that their taxpayers should not have to bail out what some see as feckless, over-spending tax-dodging southerners. In a sense this is an instance of wanting the Euro to function pretty much like the Deutschmark once did.
That particular story is dormant, Greece continues to struggle, but out of the headlines at least.
Still, a rocky, profoundly difficult road lies ahead for the Euro. There is a general agreement in the Five Presidents' Report that the countries using the Euro should move towards fiscal and financial union, including a Eurozone treasury.
The main reason that nothing has been done is that there is no agreement whether this should be on the German model or not.
Of course the two crises wouldn't, in one sense, exist if the European Union wasn't around.
There wouldn't be a Euro, for a start. And there wouldn't be a passport-free area for migrants to travel through.
So in that sense Germany's wishes wouldn't matter.
Greece could do whatever it wanted with the drachma without it worrying German taxpayers. Mrs Merkel could be a siren to Syrians and she would have to find a way of getting them to Germany, as presumably they would be stopped at borders, which had never ceased to exist.
But again, if the EU simply went away, it wouldn't erase some serious questions..
You could argue that by having to find agreement with 27 other countries, not to mention the Commission and the European Parliament, the will of Germany is tempered by a natural filter, that is bound to water down its ambitions.
Would Germany unfettered from an organisation like the EU be more modest in its ambitions?
Is the European Union no longer a restraining order, but the means by which Germany gets its way? Or is it simply the only game in town, the arena in which Germany exercises its power?
Hard questions to ask, let alone answer, but worth pondering at a critical crossroads.


The UK wants to remain signed up to the European Arrest Warrant, Home Secretary Theresa May has told MPs.

She said the UK would opt out of all 133 EU law and order measures in the Lisbon Treaty and seek to rejoin 35 of them "in the national interest".
She rejected calls by Tory MPs to scrap the warrant, but said it would be reformed to exclude minor crimes.
Labour said the announcement was "hardly a triumph of repatriation" and accused Mrs May of being soft on crime.
To shouts of "shame" from Tory benches, Mrs May said Britain would rejoin the European Arrest Warrant, but said British law would be amended to "rectify problems and increase protections" for people wanted for extradition.
"For reasons of policy, principle and pragmatism, I believe that it is in the national interest to exercise the United Kingdom's opt-out and rejoin a much smaller set of measures which help us to cooperate with our European neighbours in the fight against serious and organised crime.
"I also believe that Her Majesty's government must strike the right balance between supporting law enforcement and protecting our traditional liberties.
Q&A: European Arrest Warrant
"What I have outlined today will achieve both of those goals," she told MPs.
Mrs May promised "additional safeguards" to stop the European Arrest Warrant being used to extradite British nationals for relatively minor offences.
The Extradition Act will be amended to ensure that people can only be extradited if the country seeking them has made a decision to charge and try them, unless their presence is required to make that decision.
The law will also be changed to make sure that British citizens cannot be extradited for acts that are not an offence under British law in cases where part of the conduct took place in the UK.
She said the UK would also be seeking to opt back in to pan-EU intelligence sharing agency Europol, "provided that Europol is not given the power to direct national law enforcement agencies to initiate investigations or share data that conflicts with our national security".
The government has tabled a motion for Commons debate next week on the conditions for rejoining Europol, to be held after a vote on the wider plan to opt back in to the 35 measures.
Shadow Home Secretary Yvette Cooper accused Mrs May of a U-turn on the European Arrest Warrant, after previously suggesting it was not in the UK's interest.
"Why has it taken the home secretary three years to realise we don't want to go back to the days of the Costa Del Crime, where British criminals could flee to Spain or European criminals could find safe haven here?" she asked MPs.
Ms Cooper said many of the crime and security measures Mrs May wanted the UK to opt out of were no longer in use, had been replaced or had never been used by Britain.
"The home secretary has tried to play Britannia, clothing herself in the union jack, parading powers that she is repatriating from Brussels, but where is the substance?" she added.
She accused the home secretary of jeopardising the fight against serious cross-border crime by playing politics with the issue.
The UK will require the agreement of the EU's 27 other members to be able to re-adopt selected measures.
Some Conservative MPs have been critical of the pan-European warrant scheme, introduced in 2004 to speed up the extradition process for convicted offenders and criminal suspects across European borders.
But the Lib Dems say UK participation in the warrant, which was used to detain and extradite from Italy one of those subsequently convicted of involvement in attempted bombings in London in July 2005, makes it easier to bring offenders to justice and Labour says ditching it would be "crazy".
The European Commission said it "respects" the UK government's choice to opt out and "welcomes the UK intention to also opt back into certain measures".
"The commission will clearly need to take the necessary time to assess the indicative list of proposals for opting back in that the UK has outlined.
"The final commission position will be taken after the formal notification of the final list ie after 1 December 2014 and will be based on the criteria set out in the protocol, policy coherence and practical operability of cooperation in this area.
"At first sight, it appears that the UK has looked at the opt-ins in a pragmatic way. The commission hopes that the UK can continue to contribute actively and pragmatically to the EU wide fight against organised crime and terrorism."


A speedway rider is being treated in hospital for a head injury after an attack outside a Dorset pub.

Poole Pirates rider Darcy Ward was injured early on Saturday following an incident outside the Churchill Arms, Sturminster Marshall.
The Australian, 20, will miss the Pirates' Speedway Grand Final second leg against Swindon on Monday night.
Dorset Police confirmed a man suffered a minor head injury in the incident at 01:15 BST on Saturday.
Team manager Neil Middleditch, who was out with Mr Ward moments before the attack, admitted his rider remembers very little of what happened.
He said: "The details are a bit sketchy.
"Darcy hit his head quite hard on the ground after he took a punch and we've subsequently discovered it caused a brain bleed.
"He is still in hospital and hopefully we're going to get some good news and be able to bring him home today.
"I feel really deflated as Darcy has played such a key role in getting us to the championships."
Earlier this year, Mr Ward was cleared of a charge of sexual assault against 17-year-old girl following a trial at Bournemouth Crown Court.
The second leg of Poole Pirates' Grand Final against Swindon Robins is being held at Wimborne Road on Monday night.


Lewis Hamilton battled through a bad start and late-race rain to win an action-packed British Grand Prix

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Hamilton had to pass both Williams after losing the lead off the line and second place at a re-start following an early safety car.
But the Mercedes driver fought back to take the lead at the first pit stops.
Rain made for a chaotic end to the race but Hamilton came through to win from team-mate Nico Rosberg and Ferrari's Sebastian Vettel.
Felipe Massa took fourth ahead of Williams team-mate Valtteri Bottas, Red Bull's Daniil Kvyat was sixth, Force India's Nico Hulkenberg claimed seventh and the second Ferrari of Kimi Raikkonen came eighth.
The world champion's fifth win of the season  - extending his championship lead to 17 points - was greeted with roars of delight from the capacity 140,000 fans.
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Hamilton admitted the Mercedes' bad starts had "made the race for the fans" and, as thousands streamed on to the track to salute him on the podium, he said: "Thank you for coming out today and making my whole weekend, I really wanted to do it for you guys. I couldn't have done it without you. I'm so elated. You can't imagine how happy I am. I was tearing up on the last lap."
Hamilton's path to victory was far from smooth, however, as Massa leapt into the lead past both Mercedes from third on the grid.
Hamilton fended off a challenge from Bottas for second on the first lap, at the end of which the safety car was deployed because of a pile-up at the first corner, involving both Lotuses and both McLarens.
Three of the four cars were taken out of the race in one go, with Lotus team-mates Romain Grosjean and Pastor Maldonado appearing to collide and McLaren's Fernando Alonso half-spinning as he took avoiding action and collecting team-mate Jenson Button, whose car also retired.
Alonso was able to continue, but needed to pit for a new front wing, although the late rain shower helped the double champion beat Sauber's Marcus Ericsson to finish 10th and score his first points of a difficult year in the uncompetitive and unreliable McLaren-Honda.
At the restart, Hamilton tried an aggressive move on Massa immediately after the safety car line, which indicates the place from which drivers can begin to race and at Silverstone is on the entry to the final Vale-Club corner complex.
But Hamilton overcooked it, ran briefly off the track, and Bottas took advantage and sneaked through into second.
Bottas was initially told he could not try to pass Massa, only for Williams to relent and allow them to race.
But the Finn could not pass the Brazilian as the two silver Mercedes tracked the two white Williams to the first pit-stop period.
Hamilton was brought in first, on lap 19, and the so-called 'undercut' worked perfectly as he produced what Williams technical chief Pat Symonds called a "stunning" in-lap.
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A quick pit stop and a strong first lap out of the pits meant that when Massa and Rosberg pitted on the next lap Hamilton passed them before they were back out the circuit.
Rosberg came oh-so-close to beating Massa out - the two cars were side by side as they went down the pits, but Massa had the inside line for the corner where the pit lane rejoins the track and held on to second.
Even worse for Rosberg, when Bottas stopped on the next lap, the Finn rejoined ahead of the Mercedes and although Rosberg overtook him into Turn Four, Bottas got straight back in front through the kink at Turn Five.
Rosberg stayed stuck in fourth place until lap 36 of 52 when light rain began to fall.
At first, it hit only the northern part of the track at Luffield, Woodcote and Copse corners but a wobble from Bottas at Copse gave Rosberg the chance he needed and he took third, and then a couple of laps later moved into second past Massa at Turn Three.
The rain, which stopped and then returned with greater intensity over the whole of the track, was bad news for Williams, both of whose cars were passed by Vettel as the teams juggled with tyre choices in the intermittent rain at the end of the race.
It was an unexpected surprise for Ferrari at the end of one of their least competitive races of the season.
British GP results


Capitalism cannot work unless banks are allowed to go bust, Bank of England deputy governor Paul Tucker has said.

Mr Tucker told BBC Two's Britain's Banks: Too Big to Save? programme that despite changes to the banking system since the 2008 financial crisis, more still needs to be done.
Banks still do not hold high enough levels of capital - and no bank should be considered too big to fail.
These problems go to the very heart of the UK financial system, he said.
"If we have a system where banks take the upside but the taxpayer takes the downside something has gone wrong with capitalism, with the very heart of capitalism, and we need to repair this," Mr Tucker told BBC business editor Robert Peston.
By Robert PestonBusiness editor, BBC News
Read Robert's blog in full
"Capitalism can't work unless these financial firms at the centre of the heart of capitalism can be subject to orderly failure. The rules of capitalism need to apply to them just as they do to non-financial companies."
Mr Tucker said that big banks should be forced to hold sufficient capital - more than under current international rules - so that they have enough capacity to absorb losses if things go wrong.
Furthermore, new insolvency rules should be brought in to make it easier for banks to go bust without any losses falling on taxpayers.
This issue has been central to the debate about how to change the banking system to try to prevent a repeat of the 2008 financial crisis, when taxpayers were faced with the bill for bailing-out some of the world's biggest banks.
The governor of the Bank of England, Mervyn King, suggested in a speech in 2009 that "if some banks are thought to be too big to fail, then... they are too big".
When the financial crisis struck, the government stepped in to provide financial assistance for several UK banks.
Northern Rock was taken into state ownership, and the government now owns an 83% stake in Royal Bank of Scotland and a 41% stake in Lloyds Banking Group.
In June last year, the government set up the Independent Commission on Banking (ICB) in order to look at possible reforms to the UK banking sector.
In September, the commission said it would be considering the issue of whether banks' retail and investment operations should be split.
It also said it would look at whether "market concentration" should be reduced - with its figures showing that the top six British banks control 88% of all deposits in the country.
The commission is also looking at whether banks should have a "living will" - a declaration of how a bank would wind itself down, should any future financial crisis fatally undermine it.
The ICB has until September 2011 to make recommendations to the government.


Boreham Wood have signed Angelo Balanta on a one-year deal for a free transfer.

The 26-year-old forward was released by Carlisle United in June, after making 10 appearances for the League Two club.
Balanta has been training with the Wood during pre-season.
"I'm taking him to play up top, he'll be competing with two other forwards and he'll be judged on his work rate, attitude and, of course, his goals," manager Luke Garrard told the club website.
"Angelo knows he needs to kick-start his career here at Meadow Park, as he's not a wonder kid any longer.
"He must show me he has the desire to succeed everyday as nobody can question his ability."
Find all the latest football transfers on our dedicated page.


You don't have to spend millions of pounds to buy an original piece of art.

It's no longer just famous names who are selling their works. A growing number of art fairs and online marketplaces mean new artists starting out are also able to reach buyers well beyond their home markets.
"It's just a crazy time at the moment," says Alex Rotter, chairman of post-war and contemporary art at auction house Christie's, apologising for his late call.
We manage to speak just days before he kicks off the auction house's New York sale of 26 contemporary art works from husband-and-wife property development duo Jerry and Emily Spiegel.
This kind of single-owner collection "gathered with one breath", as Mr Rotter describes it, is rare.
The sale includes famous works by Christopher Wool and Sigmar Polke. With these two pieces valued at $20m (£15.5m) each, the 26 works are expected to raise $100m in total.
While the collection is being sold in New York, the top pieces have already been on a mini-world tour - travelling to Hong Kong, London and Los Angeles in a bid to drum up international interest.
"If you commit to buying a painting worth thousands of dollars then you want to see it first," says Mr Rotter.
Global art and antique sales totalled $57bn last year, down 11% on 2015, with the US dominating the marketplace, closely followed by the UK and China.
On a practical level, this means that delicate and often precious paintings have to travel thousands of miles without being damaged.
The value of Leonardo da Vinci's Lady with Ermine painting was considered so great that when it was sent from its Polish home to the US, it was reportedly given its own first-class plane seat, as well as an armed guard to make sure it reached its destination intact.
While this kind of treatment is exceptional, valuable paintings are typically transported in expensive protective crates complete with detectors to monitor humidity and temperature levels.
British artist Paul West says that when he secured his first sale through online marketplace Artfinder to a buyer in Australia, his initial reaction was a joyous "yes", followed by a sinking realisation that he now had to get the piece there safely.
In the three years since he joined the website, Mr West has sold around 47 paintings, with almost a third of these to buyers in the US and Australia.
He recommends lots of bubble wrap and masking tape, and to tape sponge onto the corners.
So far his worst mishap has been a hold-up at customs, which meant a painting took a month rather than a week to reach its destination.
For the 52-year-old, selling outside the UK has broadened his opportunities.
"Access to the global market is a massive plus. I was producing work I was pleased with, but apart from art fairs, it was quite hard to be seen," he says.
Artfinder founder and chief executive Jonas Almgren set up the service in 2013. He wanted to provide independent artists such as Mr West, who weren't already represented by a gallery, with a place to sell their work.
The online marketplace now features artists from 108 countries, with customers similarly global.
Originally a Silicon Valley software engineer, Mr Almgren subsequently spent a decade working in high-end galleries in New York, where a painting under $10,000 was considered affordable.
He says his experience taught him that most artists "just didn't have a chance" to succeed, and he wanted to change this.
The firm charges a 30% commission on all sales, and to address the obvious issue that it's hard to buy something so visual online, funds free returns.
Last year the firm sold £5m worth of paintings.
The company has given him an insight into how global tastes differ.
While landscape and abstract paintings are popular everywhere, the UK particularly likes paintings of cats and dogs, he says. In contrast, US buyers prefer portraits and typically buy bigger paintings, probably because they tend to have bigger homes.
The pound's current weakness against the dollar also means that US buyers can afford to spend more on UK art.
But the most important thing, says Mr Almgren, is that his firm tries to cater for all tastes.
"A gallery always has a very strong taste. We've taken that model and turned it upside down," he says.
Rise Art had similar ambitions to shake up the existing market. Set up in 2011, the start-up focuses on online sales, with prices from £200 to £30,000.
While online sales remain a small part of the overall global art market - less than 10% -  reports suggest it's a growing area.
But founder and chief executive Scott Phillips admits that no matter how good the virtual images are, an artwork "always looks better in the flesh". To help buyers' confidence, the site enables them to rent artworks and live with a piece before committing.
The firm is much more selective than Artfinder, accepting only 1% to 5% of the artists who apply to sell via the site. Rise Art also charges a higher commission of 40%.
Mr Phillips says websites like his are part of a new, more sensitive wave of disruptive firms. Unlike eBay and Amazon, which, he says, have commoditised products and been "a destructive power in some ways", Rise Art "celebrates creativity, giving artists a new vehicle for selling and showcasing their work".
While he's cagey on precise numbers, the firm now ships to 40 countries and revenue for the first three months of this year was 110% higher than a year ago.
The Affordable Art Fair (AAF) has experienced similarly rapid growth. Since starting out in London's Battersea Park in 1999, it now holds fairs in more than 10 cities around the world.
Founder Will Ramsay says the motivation behind the business was to prove that "you don't need to be a squillionaire to buy art".
While prices can be as high as £5,000 for a single painting, the AAF's average selling price in the UK is £600.
The firm makes its money by charging the galleries for the space they rent at its fairs, as well as through ticket prices and sponsors.
Recently, the firm has started online sales, an area Mr Ramsay sees as complementing the art fairs.
He owns two televisions - one to watch the video art he has accumulated and the other to watch normal TV. He says the 130 pieces of art he has collected are "memories through my life".
"Don't buy because you think it may go up in value," he advises would-be collectors, "but because you love it and want it on your wall at home."


The chancellor says he will take a "hard-nosed approach" to determine whether Pfizer's proposed £60bn takeover of UK firm AstraZeneca will deliver for UK jobs and science.

George Osborne added that it would be "extraordinary" not to engage with US pharmaceutical giant.
Pfizer's chairman Ian Read says the proposal is a "win-win for society".
Labour said the firm's promises regarding the proposed deal were "not worth the paper they are written on".
Some fear the currently-rejected deal could jeopardise Britain's science and medical industries.
Four British scientific bodies - the Society of Biology, Biochemical Society, British Pharmacological Society and Royal Society of Chemistry - have warned that recent mergers and acquisitions have led to lab closures, threatening the research base.
AstraZeneca has eight sites in the UK and about 6,700 employees.
Pfizer offered £63bn for the UK pharmaceutical firm on 2 May. If the deal were to go ahead, it would be the biggest takeover in UK corporate history.
AstraZeneca's board said the offer - the second Pfizer has made - was too low, and that it believed a major driver for the takeover was the move to establish a tax residence in the UK by changing its company structure.
MPs will investigate the proposed takeover deal next week.
Mr Osborne told BBC Radio 4's Today programme: "My job is to create both a really competitive place for businesses to come to Britain and create jobs in Britain. And we're seeing those jobs being created.
"But I'm also, on the specifics, prepared to get in the room and have a hard negotiation with very large companies and be very, very, hard-nosed about what we want to deliver in terms of good British science and good British jobs."
Pfizer has said it would relocate large parts of its business to the UK if the deal goes through. It has also suggested it wants to invest in research which could create more jobs.
BBC business editor Kamal Ahmed said Britain was highly attractive because of its low corporation tax levels and the tax incentives for scientific research.
In a series of videos posted on Pfizer's website, Mr Read said the proposed takeover was motivated by "three components of value", including combining some of the companies' products and improving efficiency.
"I think both companies have strategies that are aimed at growing and aimed at meeting patients' needs," he said.
"I believe that by combining these two companies we strengthen those possibilities. We strengthen the ability to bring products to patients. We strengthen the financial aspects of the company."
He added: "We can invest in science. I see this as a win-win for society, a win-win for shareholders, and a win-win for stakeholders."
The government has powers to veto certain deals, such as those involving defence and media companies, and apply a "public interest test". But this is rare, and its scope to intervene is also limited by the European Commission.
Prime Minister David Cameron told the Commons this week that Pfizer's assurances - including retaining at least 20% of the combined companies' research and development workforce in the UK for at least five years and basing its European HQ in Britain - were "encouraging".
But he said he was "not satisfied" with them and wanted the firm to do more.
Shadow business secretary Chuka Umunna MP said the assurances Pfizer had given ministers were "not worth the paper they are written on," as it had refused to rule out breaking up AstraZeneca in the future.
"The government could act immediately to work to put in place a stronger public interest test encompassing cases with an impact on strategic elements of our science base and seek a proper, independent assessment of the potential takeover as Labour has called for. Instead, ministers have sat on their hands," he said.
Mr Read and AstraZeneca chief executive Pascal Soriot will be questioned by the Business, Innovation and Skills Committee on Tuesday morning.
They will then face MPs on the Science and Technology Committee on Wednesday, when Science Minister David Willetts will also be asked about the government's position.
AstraZeneca employs more than 51,000 staff worldwide, with 6,700 in the UK. Pfizer - whose drugs include Viagra - has a global workforce of more than 70,000, with 2,500 in the UK.


When a loved one dies it can be difficult to come to terms with feelings of loss.

Some people confide in friends or family, while others express their emotions through other means.
Sixteen-year-old Odhran Bartley is dealing with his personal grief through music.
Odhran was only seven years old when, in 2007, his dad unexpectedly died in his sleep at the age of 39.
At the time Odhran says he wasn't ready to talk about his feelings.
"I had my mum to talk to, but I didn't really want to talk about it with anyone. I wanted to put it out there in music. I think emotion comes out best that way.
"I started rapping when I was nine, but only started writing my own material this year.
"It's a way to tell my stories and express my emotions."
The first song Odhran wrote, called I can't forget you, was based on his dad's passing.
"It was emotional writing it. I was really sad at the time but I wanted to let people know what I had to say.
"Sometimes I feel sad when I perform it, but I think it's good that I do perform it as people who have gone through similar things can relate to it".
Odhran's mum, Anthea, says she had no idea that her son was such a talented musician.
"I really was surprised that he wrote about his dad's death because even though he had talked to me about his dad dying, he hadn't talked that much about it.
"When I heard the song, I could see that he was using it as a way to talk about his emotions and to keep him going".
Having lived without his dad for nine years, Odhran says the best thing others in his position can do is "keep your head up and try to keep going".