Tammy Abraham scored a winning goal on his debut as Swansea City beat Richmond Kickers in the second USA tour game.

England under-21 international Abraham, signed on a season's loan from Chelsea, headed home in the 80th minute.
Paul Clement's side - without injured Fernando Llorente and transfer-target Gylfi Sigurdsson - took a first half lead through Oliver McBurnie.
But substitute Franck Tayou equalised on 69 minutes for the Kickers before Abraham had the last word.
Manager Paul Clement told BBC Radio Wales: "I was satisfied with the way we played, lots of players got minutes under their belts.
"Half the team played 60 minutes, the other half played 30. Lots of things to work on, but with three and a half weeks to go to the start of the season, we are moving in the right direction."
Swansea drew 2-2 with Philadelphia Union in the first game of their tour, having previously lost a friendly 1-0 at Barnet.
They complete their American training trip against North Carolina, on Saturday.


A clan association says it is surprised more Scots have not wanted to discover if they are a relative of Hollywood icon Marilyn Monroe.

The actress's mother, Gladys Pearl Monroe, had ancestral links to Scotland, according to Clan Munro USA.
It believes that an ancestor of Monroe, an alternative spelling of the Scottish surname Munro, was a Highlander banished to America in the 1650s.
Free DNA tests are available, but there has been a lower uptake than expected.
Clan Munro USA launched its offer of the test kits to Munro men of Highland origin last summer in the hope of learning more about film star Monroe's Scottish ancestry, and the wider Munro clan in general.
The search was unveiled to coincide with what would have been Monroe's 90th birthday.
The star of 1950s movies Gentlemen Prefer Blondes, Seven Year Itch and Some Like it Hot, Monroe was born as Norma Jeane Mortenson in Los Angeles in 1926.
She died of an overdose at 36 in August 1962.
So far, one man who has taken the DNA tests has had results back showing a relatedness to Monroe's line.
The association's genealogy committee said it was "surprised" more Scots had not taken up the offer of the free test kits, but remains hopeful they will be forthcoming.
Clan Munro USA hopes to trace Monroe's Scottish roots through YDNA testing. The Y chromosome is only carried by men and is passed virtually unchanged from father to son.
The society has already successfully tracked down and tested a living descendant of Monroe's great grandfather.
The results were compared to the others in its Munro DNA Project, a database of hundreds of samples provided by Munros living all over the world whose family trees have been studied.
The project includes the descendants of Munros from Easter Ross in the Highlands, also the fifth US president James Monroe and Scots soldiers who were imprisoned and then banished to the American colonies after the Battle of Worcester in 1651.
Worcester was the last battle of the English Civil Wars and involved thousands of Scots combatants.
The association said the YDNA test already done had shown that the Hollywood actress was a descendant of one of those soldiers, said to be a Highlander whose family came from Aldie, near Tain, in the Munro clan's Easter Ross stronghold.


The eagerly anticipated, two-part play Harry Potter and the Cursed Child has cast its lead characters.

Jamie Parker, currently starring in the West End show Guys and Dolls, will star as an adult Harry in the production, set 19 years after JK Rowling's books.
Noma Dumezweni, who recently stepped in at the last minute to replace Kim Cattrall in Linda at the Royal Court, will play Hermione Granger.
London Road star Paul Thornley completes the trio as Ron Weasley.
"I'm so excited with the choice of casting for Harry Potter and the Cursed Child," Rowling said.
"I can't wait to see Jamie, Noma and Paul bring the adult Harry, Hermione and Ron to life on stage next summer."
Rowling went on to address the casting of a black actress as Hermione, saying the character's ethnicity "was never specified" in her original books.
"Canon: brown eyes, frizzy hair and very clever," the author tweeted in response to a user's question.
"White skin was never specified. Rowling loves black Hermione."
Jack Thorne's two-part play - based on an original new story by Rowling, Thorne and director John Tiffany - sees Harry as both a father of three school-age children and an overworked employee of the Ministry of Magic.
While Harry grapples with a past that refuses to stay where it belongs, his youngest son Albus must struggle with the weight of a family legacy he never wanted," reads a synopsis for the show.
Parker's other stage credits include being an original member of Alan Bennett's The History Boys at the National Theatre - a role he reprised on the big screen in 2006.
The 36-year-old has since been seen in such musical productions as Assassins and High Society.
Dumezweni, 45, won a best supporting actress Olivier award in 2005 for her role in A Raisin in the Sun.
The actress, who was born in Swaziland to South African parents, also starred alongside Chiwetel Ejiofor and Audrey Tautou in 2002 film Dirty Pretty Things.
Stage regular Thornley recently featured in Simon Pegg's romantic comedy Man Up and also appeared in ITV drama Life Begins opposite Caroline Quentin.
Previews of Harry Potter and the Cursed Child begin on 7 June at the Palace Theatre, with both plays set to open on 30 July.
The casting announcement has generated significant interest on social media, something Dumezweni jokingly highlighted on her Twitter page.
"Um... So.  Just seen my feed BLOW UP," the actress tweeted on Sunday night. "What's THAT about?!"
On his own Twitter feed, Thorne said he was "so happy" the leads had been announced, describing them as "brilliant".
"Noma, Jamie & Paul will be the most brilliant three," he wrote in a follow-up post. "We're very lucky to have them."
The writer went on to "assure all doubters" that Thornley is "ginger in his soul" - a riposte to those who have suggested Ron should be played by a red-haired actor.
Parker, meanwhile, thanked his followers for the "flood of support" he has received and said he would "do [his] best for you & this phenomenal team".


Torquay United have signed striker Shaun Harrad and extended the loan of Exeter City forward Jamie Reid until the end of the season.

Harrad, 32, rejoins the Gulls after leaving Wrexham, subject to international clearance, having spent the second half of 2015-16 at Torquay.
He comes in to replace Nathan Blissett, who is set to move to Plymouth Argyle.
Reid, 22, who moved to Plainmoor on loan in the summer, has scored three times in 26 National League games.
"I was delighted to get the call and be here to help the club progress up the league table," Harrad told BBC Sport.
"I want to help us finish as high as possible, there are some talented players who came in here over the summer and we're looking to get some consistency into the performances to progress and get up that league table.
"The reason I've come back is that I'm wanted ,and as a player that's essential. Kevin (Nicholson, Torquay manager) knows what he's going to get from me and vice-versa and I think we have a good working relationship."
Nicholson commented: "His work-rate, what he brings off the pitch in terms of his leadership qualities, and how he is is as a man will be something that the lads can look up to."
On Reid's loan extension, Nicholson said he expects the forward to improve as the season goes on.
"It's great for him, great for Exeter to have a player playing regularly and it's great for us because he's shown in patches how good he is, but I think there's still a lot more to come," he added.
Find all the latest football transfers on our dedicated page.


US President Donald Trump has warned North Korea that he is considering a "pretty severe" response following the country's long-range missile test.

"They are behaving in a very, very dangerous manner and something will have to be done about it," he said.
But he moderated his comments, saying: "We'll just take a look at what happens over the coming weeks and months."
Pyongyang tested an intercontinental ballistic missile with the potential to hit the US state of Alaska on Tuesday.
Despite the ICBM's relatively short flight and eventual crash into the sea, the test has been labelled a sharp military escalation by the US.
"I have pretty severe things that we're thinking about," Mr Trump said of a possible US response. "That doesn't mean that we'll do them."
He said other nations should challenge Pyongyang's "very, very bad behaviour".
Mr Trump was speaking in Warsaw, Poland, at a joint news conference with the Polish President Andrzej Duda. He is due to meet with other world leaders at the G20 summit in Germany on Friday.
The president's comments follow those of US ambassador Nikki Haley, who told the United Nations Security Council that the US was willing to use its "considerable military forces" on North Korea "if we must".
The US and South Korea have already stepped up military drills, firing missiles into the Sea of Japan in an apparent show of strength.
Pyongyang, however, said it would not negotiate over its missile programme unless the US ended its "hostile policy" against North Korea.
Tuesday's ICBM launch was in defiance of a ban by the UN Security Council, but China and Russia, which are both veto-wielding members of the council, opposed the use of military force.
President Trump had already criticised China for its trade with North Korea, and is due to meet Chinese President Xi Jinping at the G20 summit this week.
South Korea's President Moon Jae-in has voiced concern that the North's nuclear and missile development is "proceeding much faster than expected".
Speaking in Berlin on Wednesday, where he met German leader Angela Merkel, he said they would "examine possibilities of ramping up sanctions".
At the UN Security Council meeting in New York, France's ambassador said it also favoured a new resolution on North Korea to tighten sanctions.
Russia, which condemned the test, said the possibility of using military measures "should be excluded".
China's ambassador Liu Jieyi echoed similar sentiments and said "military means must not be an option".
He repeated China and Russia's proposal that North Korea should halt its missile and nuclear programmes in exchange for US and South Korean military exercises in the region being frozen. They also propose reversing plans to deploy a controversial anti-missile system in the South.
The "US strategy of strength" combined with pressure and engagement "will never work", state news agency KCNA said.
Unless the US stopped its "hostile policy", North Korea would "never put the nuke and ballistic rocket on the negotiating table".
North Korean leader Kim Jong-un was earlier quoted as saying that Tuesday's launch was a "gift" to the Americans on their Independence Day, and that he had ordered officials to "frequently send big and small 'gift packages' to the Yankees".
Pyongyang said the Hwasong-14 ICBM had reached an altitude of 2,802km (1,731 miles) and flown 933km for 39 minutes before hitting a target in the sea.
North Korea, it said, was now "a full-fledged nuclear power that has been possessed of the most powerful inter-continental ballistic rocket capable of hitting any part of the world".
But while experts agree that the test shows Pyongyang has a long-range projectile, many are sceptical that its missiles can successfully deliver nuclear warheads.
North Korea's missile programme in detail


Bernie Ecclestone has been removed from his position running Formula 1 as US giant Liberty Media completed its $8bn (£6.4bn) takeover of the sport.

Ecclestone, 86, who has been in charge for nearly 40 years, has been appointed chairman emeritus and will act as an adviser to the board.
Chase Carey has had Ecclestone's former role of chief executive officer added to his existing position of chairman.
Liberty has also brought ex-Mercedes team boss Ross Brawn back to F1.
The former Ferrari technical director, who had been acting as a consultant to Liberty, has been appointed to lead the sporting and technical side of F1.
Ecclestone said earlier on Monday he had been "forced out".
He told Germany's Auto Motor und Sport: "I was dismissed. This is official. I no longer run the company. My position has been taken by Chase Carey."
Ecclestone, who added he did not know what his new job title meant, declined to comment when approached by BBC Sport, who revealed on Sunday he would leave his job this week.
Liberty began its takeover of the sport in September and earlier in January cleared the last two regulatory hurdles.
The deal was completed on Monday and Liberty Media is to be renamed the Formula 1 Group following the takeover.
As well as Brawn's return, former ESPN executive Sean Bratches has been hired to run the commercial side of the sport.
Brawn, 62, masterminded all seven of Michael Schumacher's world titles at Benetton and Ferrari and also won the championship with Jenson Button with his own team in 2009. He then moved to Mercedes, where he laid the foundations for Lewis Hamilton and Nico Rosberg's title wins.
Both he and Bratches will report to Carey, a former long-time lieutenant of media mogul Rupert Murdoch and chairman of his 21st Century Fox company.
Bernie Ecclestone: "I'm proud of the business that I built over the past 40 years and all that I have achieved with Formula 1. I would like to thank all of the promoters, teams, sponsors and television companies that I have worked with.
"I'm very pleased that the business has been acquired by Liberty and that it intends to invest in the future of F1. I am sure that Chase will execute his role in a way that will benefit the sport."
Chase Carey: "I am excited to be taking on the additional role of CEO. F1 has huge potential with multiple untapped opportunities. I have enjoyed hearing from the fans, teams, [governing body] FIA, promoters and sponsors on their ideas and hopes for the sport.
"I would like to recognise and thank Bernie for his leadership over the decades. The sport is what it is today because of him and the talented team of executives he has led, and he will always be part of the F1 family.
"Bernie's role as chairman emeritus befits his tremendous contribution to the sport and I am grateful for his continued insight and guidance as we build F1 for long-term success and the enjoyment of all those involved."
Greg Maffei, president and CEO of Liberty Media Corporation: "We are delighted to have completed the acquisition of F1 and that Chase will lead this business as CEO. I'd like to thank Bernie Ecclestone for his tremendous success in building this remarkable global sport."
Zak Brown, executive director, McLaren Technology Group: "Formula 1 wouldn't be the international sporting powerhouse that it is today without the truly enormous contribution made over the past half-century by Bernie Ecclestone. Indeed, I can't think of a single other person who has had anything like as much influence on building a global sport as he has.
"Today is a day on which we should all pay tribute to a remarkable visionary entrepreneur called Bernie Ecclestone, and to say thank you to him too."
Murray Walker, F1 commentator, speaking to BBC Radio 5 live: "Formula 1 owes him an immeasurable debt. He is a very tough businessman but if he shakes your hand you don't need a contract. He's as good as his word.
"The most important thing under Bernie's rule was the safety aspect. Formula 1 has been absolutely transformed. There was a time when four or five people were being killed every year but Bernie, with the help of Professor Sid Watkins, transformed that situation."
Ecclestone, the former team boss of Brabham, began in the 1970s as a representative of his colleagues in negotiations with circuits, television and authorities and slowly moved into a position of almost absolute power.
He was central in turning F1 from a relatively minority activity into one of the biggest television sports in the world outside the Olympics and the football World Cup.
After selling Brabham in the late 1980s, he moved full-time into administration.
He took over the ownership of the commercial rights of F1 from the teams in the mid-1990s. He then struck a deal in 2000 with his long-time ally Max Mosley, then president of the FIA, to lease them for 110 years at what critics said was an absurdly low price of $360m (£287m).
That set in motion a series of sales where the rights were passed from one entity to another, a process that led Ecclestone to stand trial for bribery in Germany in 2014. The case was dropped after a payment of $100m (£79m) without presumption of guilt or innocence. Subsequently Liberty took over from previous owner CVC Capital Partners.
Ecclestone built F1 into a sport that could be valued by one of the world's biggest media groups at $8bn.
He did this by building up F1's exposure on television, forcing companies to transmit the whole championship rather than cherry-picking the odd race here and there as had been normal until the early 1980s.
But he has been criticised for his authoritarian grip on the sport and his controversial approach.
In recent years, his demands for ever-higher fees from race tracks led to several European races struggling to make ends meet. His decision-making was also questioned, particularly over issues such as the introduction of double points for the final race of the 2014 season, and the quickly abandoned change of the qualifying format in 2016.
A prize-money structure he created in the early years of this decade is believed by many insiders to be unfairly skewed in favour of the bigger and richer teams, and the governance system he set up at the same time has led to a log-jam when it comes to decision-making.
Equally, his public utterances were sometimes ill-advised, such as praising Adolf Hitler for "being able to get things done" and calling women "domestic appliances".
And some of his choices of locations for new races were also controversial - in countries such as Bahrain, Russia and Azerbaijan which secured huge fees for CVC but were criticised because of the regimes' records on human rights.
Media playback is not supported on this device
Liberty has not publicly revealed what changes it will make to F1 but insiders say it plans to act on many of the areas that were considered a weakness under Ecclestone.
In particular, it wants to exploit digital media, an area with which Ecclestone refused to engage, and it intends to invest in securing the futures of certain races which it considers valuable.
It also wants to grow the sport in the USA, where F1 has long struggled to gain a sure foothold and promote it much more extensively, talking of creating "20 Super Bowls", in terms of making much more of the build-up to each race.


Bosses at a housing complex for the over 55s have introduced a ban on alcohol and karaoke following a festive bust-up.

The Sentinel reported Sanctuary Supported Living enforced the ban in communal areas at Baskeyfield House, Stoke-on-Trent, following a dispute over a "59p decoration".
Residents said they are being "treated like children".
The Sanctuary Group cited "unacceptable behaviour" for the "short-term" ban.
More on this and other stories from Stoke and Staffordshire
Resident Geoff Lawton told BBC Radio Stoke: "The management has decided we can't have any form of entertainment after 5pm."
He added: "We can't drink alcohol in the communal area, which is a public area.
"Somebody who's middle aged comes along and starts treating older people like children".
Julie Swinnerton, who lives in the flats and owns karaoke equipment used by fellow residents, said there is a split between those who enjoy entertainment and those who don't.
She said one lady started an argument over a "59p decoration" at a Christmas party and it "escalated".
"They took my karaoke equipment away and said I could only have it back if I kept it in my room", she added.
Tracey Spencer, service manager at Sanctuary Supported Living, said: "We have a responsibility and a duty of care to all residents at Baskeyfield House and continue to work with them to ensure a welcoming environment for all.
"The decision to temporarily suspend all activities within the communal areas was taken after unacceptable behaviour at a recent social occasion."
Baskeyfield House is an extra care scheme, made up of a number of individual apartments where residents live independently.


Warrenpoint Town's Arbitration hearing to contest their relegation from the Irish Premiership takes place on Thursday 9 June.

An IFA Disciplinary Committee opted not to punish Carrick Rangers over a touchline ban irregularity, which resulted in Carrick staying up.
The Northern Ireland Football League have now fixed provisional dates for the promotion play-off.
Warrenpoint may face Institute on June 14 and 17 if they win their appeal.
If 'Town fail to be reinstated to the top flight, Ballinamallard and Institute will play the second leg of their play-off on Wednesday 15 June.
Ballinamallard won the first leg 2-1 at Institute on 6 May before off-field events led to the postponement of the second leg.
The IFA granted NIFL an extension to the season due to the uncertainty of the various appeals and Arbitration processes.
However only players eligible to participate in the first leg of the play-off are eligible to play in the second leg.
Proposed play-off games have a 19:45 kick-off.


The Rolling Stones have confirmed they're working on a new, blues-inspired album for release this year.

"We're actually in the studio in the moment cutting new stuff," Keith Richards told BBC 6 Music.
Guitarist Ronnie Wood added that the band recently "cut 11 songs in two days. Just 'bang' - like that."
"It was a surprise to us. We didn't intend doing it," he told Matt Everitt. "I wish I could play them to you now. I'm so excited about them."
The Rolling Stones haven't released a studio album since 2005's A Bigger Bang, although they wrote two new songs for the 2012 compilation record Grrrr!
The sessions have included new material and a series of blues covers, including songs by Little Walter and Howlin' Wolf.
"They sound so authentic it's frightening," said Wood.
"We didn't spend any time rehearsing them or anything. We just picked a song that suited Mick's harmonica or a guitar riff... and they worked out pretty good.
"It was like, 'this is what the Stones do, we play blues.'"
"It's sounding really good," added Mick Jagger. "We did one session before Christmas. We'll probably do more."
"It's very easy and free," said drummer Charlie Watts. "Keith plays the same now as he ever did. He sits there and plays a song and if something comes to him, he'll put that into it."
Wood said the new music would be released "sometime this year", while Jagger said the band would be announcing more shows in the coming months.
"We'll come back to the UK, indeed," he said. "It doesn't feel very long since we played [here] but actually it's ages ago now."
"I think our main thing is playing live these days," Richards added. "Within the band, we always feel like the next show is going to be better.
"For a bunch of reprobates we have an incredible dedication to our job."
The band were speaking at the launch of Exhibitionism, a career retrospective at London's Saatchi Gallery.
Billed as the largest exhibition of Stones memorabilia ever mounted, it includes a recreation of the studio where they recorded Sympathy For The Devil, and the band's filthy first flat in Edith Grove, Chelsea.
It also includes key instruments, album art, diary entries, tour posters and the band's flamboyant outfits.
But, as Richards told 6 Music: "I don't remember wearing any of it."


Detectives investigating the rape of a woman in Renfrewshire have asked for help to trace her missing trousers.

The 27-year-old was attacked by a man on a path near Wallace Primary School, Elderslie, at about 20:00 on Monday.
Police have urged people to check gardens and bins for discarded clothes.
The suspect was white, aged between 35 and 50, with dark hair, receding on top, and of medium to stocky build He was clean shaven and wearing dark trousers and a light T-shirt.
The woman had been walking on the pathway between Byres Road and Glenmalloch Place in Elderslie when she was struck by the man, causing her to fall over. He then raped her.
Det Insp Louise Harvie, of Police Scotland, said: "As part of this ongoing investigation, officers have carried out a full search of the area.
"As a result of these inquiries, it has been established that the woman's trousers are missing.
"Officers are, therefore, asking local residents in that area to check their gardens and bins for any item of discarded clothing which they don't recognise as belonging to them.
"Officers have been carrying out extensive inquiries in the local area including door-to-door inquiries and are reviewing CCTV footage from the surrounding areas."
She added: "The man responsible must be traced and I would re-appeal to anyone with information that may assist this ongoing inquiry."


Two men who boasted they had "got away with murder" after a dispute with a neighbour have been jailed for life with a minimum of 14 years each.

Harry Hood, 46, and Ross Russell, 35, attacked Arthur Green at his home in South Ayrshire in November 2014.
The High Court in Glasgow heard how Hood's parents said they had endured years of trouble at the hands of 60-year-old Mr Green and his family.
The judge criticised the local council's handling of the dispute.
Judge Bill Dunlop QC suggested South Ayrshire Council should not have dealt with it by encouraging the alleged victims to move.
"The reaction of the council which I heard was disturbing," he said.
"That they should make themselves homeless and move to an area away from the place they loved living in and to leave their home was frankly disappointing, wholly inadequate and on one view, cruel.
"That failure to act on the part of the council was explained to the court as due to there being no corroboration, as a lawyer I can say that's nonsense.
"I am afraid I am driven to conclude that the council went for the easy option, persuading the good guys to move would be simple and more straightforward than evicting those causing the trouble."
A jury had heard how Harry Hood flew into a rage when it emerged his parents' window had been smashed.
Hood and his violent friend, Russell, later went to Mr Green's home where he was punched, kicked and stamped to death.
The men fled the scene with Hood heard saying: "If I murdered him, I will happily do time for it."
Mr Green's young grandson discovered his body the next day.
The pair boasted they had "got away with murder" after police initially believed Mr Green had fallen.
After a new investigation, Hood, from Ayr, and Russell, from Maidens, were arrested.
Hood's 76-year-old father, also called Harry, told the court how Mr Green had been a "nightmare" to live next to.
Both Hood and Russell gave evidence during the trial and effectively blamed each other.
Dale Russell, from Girvan, Ayrshire, had also been charged with murder before prosecutors dropped the allegation during the trial.
He instead pled guilty to attempting to defeat the ends of justice by setting fire to his brother's trainers.
He was ordered to carry out 300 hours of unpaid work.


A Berlin court has sentenced two men to life on murder charges for killing a motorist during an illegal car race in the first case of its kind in Germany.

The men in their 20s were driving at up to 160km/h (100 mph) on a main shopping street when one smashed into another car, killing the 69-year-old driver.
Prosecutors argued that the men had accepted their actions were potentially lethal, showing "conditional intent".
Defence lawyers had called for charges of manslaughter and dangerous driving.
One of the defendants, named only as Hamdi H, appeared bewildered by the ruling, Bild newspaper reported.
But Judge Ralph Ehestadt at the Berlin regional court told him: "Of course you had no intent to kill. You did not want to kill Mr W in his jeep. But you were acting with conditional intent."
Hamdi H and his co-defendant, named as Marvin N, encountered each other in their Audi and Mercedes cars in February last year.
They accelerated down the Kurfurstendamm - one of the German capital's most popular shopping streets - before Hamdi H crashed into the jeep. Marvin N then crashed into Hamdi H's car. The collisions flung the jeep 70m down the road.
Both men walked away from the crash with minor injuries.
During the case a psychologist said one of the men had "massively overestimated himself" as a driver, wanted to win the race to "enhance his ego" and had no sense of his own guilt, Deutsche Welle reported.
The judgement at the Berlin regional court is not yet legally binding, Deutsche Welle said.


Oxford city centre is to become a low emission zone (LEZ) from 1 January 2014 under council plans.

The plan is a bid to improve air quality and reduce transport-related emissions, said Oxford City Council and Oxfordshire County Council.
The LEZ will only apply to buses which account for up 80% of the pollution in the city centre, authorities said.
Oxford's LEZ will be the second to be introduced in the UK outside of London.
Labour councillor John Tanner, of Oxford City Council, said buses would also be banned from keeping their engines running for more than one minute at a bus stop.
Mr Tanner said buses which break the rules could lose their operator licence, granted by the Traffic Commissioner.
"Oxford City council will continue to press for other improvements until nitrogen dioxide pollution is below 40 parts per million everywhere in the city," he added.
Conservative councillor David Nimmo Smith, cabinet member for environment on Oxfordshire County Council, said the city had some of the highest bus use in the UK.
"Buses are vital to Oxford's economy and environment so I'm delighted to see the LEZ coming into effect to make the city's buses even cleaner," he added.
However, the Oxfordshire Green Party said the new LEZ didn't go far enough.
"A LEZ is long overdue - air quality is continuing to deteriorate in the city centre," said Green group leader Craig Simmons.
"Our concern is that the limited measures proposed will have a minimal effect.
"It applies only to buses, many of which were already in service last year, when air quality again declined. And there are several exemptions."
Mr Simmons said a "clear plan" to extend the LEZ to cover all polluting vehicles was needed.
The city council said the LEZ was developed in response to Oxford City Council's last Air Quality Action Plan (AQAP 2006).


Cheltenham overcame the 18th-minute dismissal of midfielder Kyle Storer to hold in-form Mansfield to a draw at Whaddon Road.

The flashpoint arrived when Storer launched into Jamie McGuire with a full-blooded challenge on the halfway line in front of the visiting bench.
Referee Charles Breakspear wasted little time in brandishing a straight red card, with Robins manager Gary Johnson sent from the dugout in the aftermath.
Cheltenham were rocked, but the Stags - beaten just once in their previous 12 League Two outings, could not find a way through as Ben Whiteman scuffed horribly off target from two presentable openings.
The hosts began the second half on the front foot with Mansfield skipper Lee Collins getting a vital touch on Will Boyle's on-target header shortly before Liam Davis hit the crossbar straight from a corner on 51 minutes.
Whiteman miscued again from 18 yards just before the hour and Mansfield substitute Shaquile Coulthirst lifted the ball over from inside the box late on as Cheltenham secured a fourth successive clean sheet.
Match report supplied by the Press Association.
Match ends, Cheltenham Town 0, Mansfield Town 0.
Second Half ends, Cheltenham Town 0, Mansfield Town 0.
Attempt blocked. James Rowe (Cheltenham Town) right footed shot from outside the box is blocked.
Rhys Bennett (Mansfield Town) is shown the yellow card for a bad foul.
Liam Davis (Cheltenham Town) wins a free kick in the attacking half.
Foul by Rhys Bennett (Mansfield Town).
Harry Pell (Cheltenham Town) wins a free kick in the attacking half.
Foul by Krystian Pearce (Mansfield Town).
Attempt missed. Shaquile Coulthirst (Mansfield Town) right footed shot from the right side of the box is just a bit too high.
Attempt blocked. Liam Davis (Cheltenham Town) right footed shot from outside the box is blocked.
Substitution, Cheltenham Town. James Rowe replaces Billy Waters.
Corner,  Cheltenham Town. Conceded by Hayden White.
Delay over. They are ready to continue.
Attempt missed. Yoann Arquin (Mansfield Town) right footed shot from outside the box is close, but misses to the left.
Corner,  Mansfield Town. Conceded by Jack Barthram.
Substitution, Mansfield Town. Alfie Potter replaces Jamie McGuire.
Substitution, Cheltenham Town. Jordan Cranston replaces Carl Winchester.
Substitution, Cheltenham Town. Daniel Wright replaces Kyle Wootton.
Attempt missed. Harry Pell (Cheltenham Town) right footed shot from outside the box is close, but misses to the right from a direct free kick.
Foul by Jamie McGuire (Mansfield Town).
Billy Waters (Cheltenham Town) wins a free kick in the defensive half.
Foul by Yoann Arquin (Mansfield Town).
Daniel O'Shaughnessy (Cheltenham Town) wins a free kick in the attacking half.
Attempt missed. Harry Pell (Cheltenham Town) right footed shot from outside the box is close, but misses the top right corner.
Substitution, Mansfield Town. Yoann Arquin replaces Alexander MacDonald.
Attempt missed. Lee Collins (Mansfield Town) right footed shot from outside the box is close, but misses to the left.
Hand ball by Alexander MacDonald (Mansfield Town).
Substitution, Mansfield Town. Shaquile Coulthirst replaces Pat Hoban.
Liam Davis (Cheltenham Town) is shown the yellow card for a bad foul.
Benjamin Whiteman (Mansfield Town) wins a free kick in the defensive half.
Foul by Liam Davis (Cheltenham Town).
Attempt missed. Benjamin Whiteman (Mansfield Town) right footed shot from outside the box misses to the left.
Foul by Pat Hoban (Mansfield Town).
William Boyle (Cheltenham Town) wins a free kick in the attacking half.
Lee Collins (Mansfield Town) wins a free kick in the attacking half.
Foul by Harry Pell (Cheltenham Town).
Attempt missed. Alexander MacDonald (Mansfield Town) right footed shot from the left side of the box misses to the left.
Jack Barthram (Cheltenham Town) is shown the yellow card for a bad foul.
Malvind Benning (Mansfield Town) wins a free kick on the left wing.
Foul by Jack Barthram (Cheltenham Town).


A board looking at the future of Welsh accommodation at Aberystwyth University is calling for it to be overhauled.

Students climbed on to the roof of the Welsh-language hall of residence, Pantycelyn, last June to protest its proposed closure.
The Pantycelyn Project Board was set up to secure its future and its report on Friday has tabled two options for more than Â£8m in improvements.
The university's council will discuss the report in its meeting next month.
Protestors have accused the university of not valuing the language enough.
The university had recommended the halls close to make them "fit for purpose".
The report outlines options for developing Welsh-medium student accommodation in Pantycelyn with 199 rooms, including 114 with en suite facilities or the preferred choice - 200 en suite rooms.
The report calls on the university council to commit to renovating and reopening Pantycelyn by September 2019.


Millions of energy users in Britain are about to get a new metering system - smart meters - technology which has been rejected by Germany and found not to be cost-effective by other nations.

Smart meters send information on energy usage directly back to the energy supplier, which eliminates the need for meter readings.
Crucially, they also let the customer know just how much electricity or gas they are consuming during the day. This revelation is expected to change our behaviour, so that we switch off lights, turn down heating, and generally use less energy.
The EU has said that all its members must provide smart meters by 2020 as long as there is a positive economic case to do so.
Germany employed accountancy firm Ernst and Young to conduct a cost-benefit analysis and they concluded it did not make economic sense, because most householders did not use enough energy to make it value for money. As a result, Germany declined to stage a mass roll-out.
Other countries have adopted smart meters with varied success. Auditors in Australia and Canada found it was too expensive.
Andrew Evans, from the auditor general's office in Victoria, Australia, said there would not be any overall benefit to consumers, and the net cost was $320m (£170m) paid by consumers through higher energy bills.
The British government has committed  to getting 53 million smart meters into our homes and small businesses by the end of 2020, at an estimated cost of £11bn. That does not include Northern Ireland, which is still assessing whether smart meters would be in consumers' interests.
There are already two million meters installed in households and businesses in the rest of the UK.
Pensioner Maureen Fenlon and her husband Viv opted to have smart meters installed in their Lincolnshire bungalow a year ago. Mrs Fenlon was proud to show me the small  "in-home display" which shows the cost of electricity and gas used during the day.
She said seeing the real cost of using appliances has encouraged her to use her microwave more than her oven, which has saved money on bills.
That kind of behaviour may cut our bills, it is claimed, by an average £26 a year per household up to 2020. According to government estimates, that could mean a total saving of around £6bn by then.
The Department of Energy and Climate Change says: "Smart meters will help families and businesses take control of their energy use, bringing an end to estimated bills and helping bill payers to become more energy efficient."
However, the cost of the roll-out is high, and the estimated savings rely on millions of us being willing to change our behaviour.
Meanwhile, the second stage of introduction is running late. This involves a second generation of smart meters, and a new national communications network which will allow the transmission of data between smart meters and all energy suppliers.
There has been criticism of how the entire smart meter project has been planned.
In other countries, a central administration has handled the roll-out whereas in the UK, the government left it up to the energy companies.
Some homes do not get enough wireless signal for the current generation of smart meters to work.
If someone like Mrs Fenlon switches suppliers today, the in-home display may not work with the new supplier's technology;  the first-generation smart meter effectively becomes "dumb". That should change in the next couple of years when the new communications network is up and running.
The so-called big six energy suppliers are hoping to introduce a new kind of pricing to go with smart meters, a system used elsewhere in the world called time of use tariffs.
This could mean that you are charged much more at peak times, say between 16:00 and 20:00, for using electricity. The idea is that you are being nudged to use your appliances when it is cheaper.
Critics worry that this might have damaging effects on vulnerable groups of people such as the elderly and those on low incomes.
According to Stephen Thomas, Emeritus Professor of Energy Policy at the University of Greenwich, older or vulnerable people who are faced with extra high costs of using energy on a cold winter evening may choose to switch off and be cold.
The answer is that these "time of use" tariffs will be purely voluntary, according to Rosie McGlynn, director of new energy services at Energy UK. She argues people will be able to plan ahead better and save on their bills when they have a smart meter, and those currently on pre-payment meters will pay lower prices than they do now.
Smart meters are not compulsory, although the publicity campaigns do not give that fact much prominence. The energy companies are footing the bill for installing smart meters, but they acknowledge they will pass costs on to the customer. So, even if you do not want one, you are going to be paying part of the £11bn cost.
Listen to the Moneybox special on smart meters on BBC Radio 4 at 12:00 GMT on Saturday, 26 March


Warrington Wolves finally claimed their first Super League win of the season at the eighth attempt to climb off the bottom of the table.

After Tom Briscoe put Leeds ahead, Warrington hit back with two tries from Ryan Atkins to lead 12-4 at the break.
Tom Lineham's converted try stretched Wire's lead before Leeds replied with tries from Matt Parcell and Joel Moon.
But Kurt Gidley then crossed, Declan Patton adding a fourth conversion of the night before his late drop-goal.
Warrington were fortunate not to get a red card inside the first minute for second-row forward Ben Westwood, who was only yellow carded for his late hit on Liam Sutcliffe, whose night ended prematurely with concussion.
After Westwood was sent to the sin-bin for the stiff-arm late tackle which put Sutcliffe out of the game, Leeds quickly cashed in down the right.
On his 400th game for the club, Danny McGuire fed Briscoe, who twisted into a tackle before somehow propelling himself across the line for his second Super League try of the season.
But, after Ashton Golding missed the kick, Warrington were ahead when Lineham touched back for Atkins to cross in the left corner, Patton adding the extras.
Atkins then crossed for a second, the try still being awarded despite the Wire centre appearing to lose control of the ball just before touching down.
Patton again converted, doing so again when the reprieved Westwood played Lineham in at the left corner early in the second half.
Leeds responded with tries in quick succession, before Gidley's try on 68 minutes, again converted, took the hosts out of sight again to end the Rhinos' four-game winning run.
Warrington coach Tony Smith:
"It was late (Ben Westwood's challenge on Liam Sutcliffe) but there was nothing in it in terms of anything else. It was warranted, the 10 minutes."
"There might be a couple of other things, chicken wings and those sort of things, that crept in there but we will have a look at that later on.
"I'm pleased for the players. We had faith it was coming. There is not much difference between winning and losing. Leeds have played that standard this season and won games. It shows there is not a lot between us.
"It is a tough competition and, if you are off in some areas, it is hard to turn that around in terms of results. We know we are going to climb the ladder. We've not had the start we wanted but the way we finished will be the way we want it to be."
Leeds boss Brian McDermott:
"I haven't seen it enough (the Westwood incident). "He certainly doesn't miss but I wouldn't comment on it. And it wasn't the the reason we lost the game.
"If you were to go through our performance in detail you'd find one or two things where we weren't as good as we should be.
"We didn't get much momentum with the ball in the first half but Warrington's kicking game was not far off a 10 out of 10 tonight.
"We wanted to be more inventive with the ball. I find it hard to be critical of my team, though. They dug in and showed a lot of spirit."
Warrington: Ratchford; Russell, T King, Atkins, Lineham; Patton, Gidley; Hill, Clark, Sims, Westwood, Hughes, Westerman.
Replacements: Philbin, Dwyer, Evans, G King.
Sin Bin: Westwood (1)
Leeds: Golding; Briscoe, Watkins, Keinhorst, Hall; McGuire, Moon; Garbutt, Burrow, Cuthbertson, Ablett, Sutcliffe, Jones-Buchanan.
Replacements: Mullally, Parcell, Delaney, Walters.
Attendance: 10,035
Referee: James Child (RFL)


Human rights group Amnesty International has said there was an "alarming" increase in death sentences around the world in 2014.

In its annual review of death penalty use across the planet, it said some countries were using it in response to "real or perceived" security threats.
More than 500 more death sentences were issued than in 2014, mainly because of sharp rises in China and Nigeria.
However, excluding China, the number of actual executions reportedly dropped.
Amnesty recorded 607 executions in 2014, down almost 22% on 2013. However, this figure does not include China, which executes more people than the rest of the world put together but keeps the exact numbers a state secret.
Executions were recorded in 22 countries in 2014, the same number as in the previous year.
Apart from China, Amnesty said the world's top executioners in 2014 were:
In Egypt, hundreds of people have been sentenced to death in mass trials over the past two years in a crackdown on Islamists. The trials have drawn widespread international criticism, with the UN describing them as "unprecedented".
In Nigeria, 659 death sentences were recorded in 2014, Amnesty said, a jump of more than 500 compared with the previous year.
Military courts handed down death sentences against dozens of soldiers during the year in separate trials. They were convicted of mutiny in the context of the armed conflict with Islamist militants Boko Haram.
Earlier this month Pakistan lifted a seven-year moratorium on executions in the wake of a Taliban massacre at a school in the city of Peshawar in December.


Thousands of people have attended the funeral of a leading lawyer shot dead in Myanmar's commercial capital, Yangon, on Sunday.

Ko Ni, who was an adviser to Aung San Suu Kyi's National League for Democracy (NLD) party, was shot in the head at Yangon airport.
A suspect has been detained but there are no details on the motive.
Ko Ni, who the NLD described as "irreplaceable", was a rare prominent Muslim in a Buddhist-majority nation.
It is not clear whether his religion was a factor in his death. The well-respected constitutional lawyer had spoken up in defence of rights for Muslims and had also criticised the military's grip on power.
Political killings are extremely rare in Myanmar, also called Burma. A taxi driver who tried to stop the gunman escaping was also shot dead.
Ms Suu Kyi does not appear to have made any public comments yet. But in a statement, the NLD said: "We strongly denounce the assassination of Ko Ni like this as it is a terrorist act against the NLD's policies."
Senior NLD leader Tin Oo described Ko Ni's death as a "great loss for the country, for democratic forces and for us (the party)".
Rights group Amnesty International said the killing had "all the hallmarks of an assassination". It called for a thorough investigation into the death of a man it described as a "tireless human rights campaigner".
Large crowds of mourners, including MPs, activists and Buddhist monks turned out for his funeral at a Muslim cemetery.
"All I want to say is, of course we are all shocked and really sad,'' said US Ambassador Scot Marciel. "I knew Ko Ni and his commitment to his country and democracy.''
Exactly 24 hours after he was shot dead Ko Ni's funeral took place on the outskirts of Yangon. A large, emotional crowd, mainly of Muslims but including Christians and Buddhists, filled the Ye Way cemetery.
Among them was a three-year-old called Erfan. He'd been in the arms of his grandfather at Yangon airport, when the assassin walked up behind them and shot Ko Ni in the head. Incredibly Erfan appears to be fine, chuckling away as his mother sobbed.
As I soon discovered, publically asking people why they think Ko Ni was killed is a sensitive matter. Among those at the funeral willing to talk, most thought he'd been assassinated for his work on constitutional affairs.
As well as being a top lawyer, Ko Ni was a legal adviser to Aung San Suu Kyi's political party. He's been credited with finding loopholes in the existing military-drafted constitution and in particular with creating the far-reaching role of state counsellor, which Ms Suu Kyi now occupies.
So far there's been no word from the police on what the alleged assassin has been saying in custody. The authorities in Mandalay say that Kyi Lin spent more than a decade in prison for illegally dealing in Buddha's heads and antiquities, before being released in a presidential amnesty in 2014.
Ko Ni was shot at point blank range outside the terminal as he held his grandson. The suspect then fled but several taxi drivers chased him, according to The Irrawaddy. The suspect shot one driver, U Nay Win, before being detained by police.
The suspect has been named by police as Kyi Lin, 53, but there is no information as to motive.
Ko Ni had been returning from a meeting in Indonesia to discuss sectarian tensions in Rakhine state when he was killed.
Anti-Muslim feeling is high in Myanmar, and there is significant public support for a military operation in Rakhine, which is home to thousands of Rohingya Muslims.
The military says it is restoring security after a deadly attack on police officers in October last year that it blamed on Rohingya. But it has been accused of widespread human rights abuses, including arbitrary arrests, beatings and the burning of villages.
Rohingya are denied citizenship and are considered illegal immigrants by the government. The NLD runs the current government but the military-drafted constitution ensures the military retains power over key institutions.
Ko Ni's daughter, Yin Nwe Khine, told Reuters he was "often threatened" because he had spoken out against the continuing influence of the military on politics.
"We were warned to be careful, but my father didn't accept that easily. He always did what he thought was right.
"A lot of people hate us because we have different religious beliefs, so I think that might be why it happened to him, but I don't know the reason."


A flagship academy chain gave £5,000 to the Labour Party and spent £20,000 with a consultancy firm run by the wife of a school director, a report has found.

Perry Beeches Academy Trust, once praised by ex-prime minister David Cameron, has been criticised by watchdog the Education Funding Agency.
It breached Charity Commission regulations by sponsoring the Labour Finance and Industry Group. The money has since been returned, the EFA said.
The trust has adopted recommendations.
The EFA investigated the trust - which runs five schools in the city - in March after allegations of "novel and contentious use of trust funds and assets" and irregular expenditure.
More updates on this and other stories in Birmingham and the Black Country
Information from a whistleblower prompted the investigation, which found an additional salary of £160,000 was paid to chief executive Liam Nolan, over two years, through a third-party agreement - on top of his £120,000-a-year salary. He resigned in May.
The agency's full report, revealed on Thursday, details breaches and failures by the trust to follow its procurement processes.
It looked at how contracts and jobs were awarded and highlighted the employment of Mr Nolan's nephew and niece, the latter being promoted six times in three years.
There was also no evidence of tendering for contracts for legal and PR services worth thousands of pounds or reasons for the payments.
EFA key findings:
In a statement the trust said the report related to historical allegations and board of trustees resigned in April and a new management structure was in place.
The new team has been working "very closely" with the EFA and department for education "to move Perry Beeches The Academy Trust and its schools forward to a better future".
"All recommendations in the report have been adopted by the trust," the spokesman added.


Taoiseach (Irish Prime Minister) Enda Kenny has appointed a new Cabinet just hours after he was re-elected to govern for a second term.

The ministers were announced on Friday afternoon, 70 days after voters went to the polls to elect a new government.
Charlie Flanagan, who has been heavily involved in peace talks in Northern Ireland, has been re-appointed as minister of foreign affairs.
The Cabinet also includes a number of independent elected representatives.
The support of independents was necessary to allow Mr Kenny's Fine Gael party to lead a minority government, after the general election of 26 February produced a hung parliament.
Among the new independent ministers is Katherine Zappone, a high-profile campaigner for same-sex marriage who was born in the US but moved to the Republic of Ireland 28 years ago.
In May 2015, she famously proposed to her wife on live state television after Irish voters approved the introduction of same-sex marriage in a referendum.
Ms Zappone, who became the first openly lesbian member of the Irish parliament earlier this year, has been appointed as minister for children and youth affairs.
Other independent ministers include former business journalist and senator Shane Ross and Denis Naughten, who resigned from Fine Gael in 2011 in protest at cuts to hospital services.
The new Cabinet consists of:
Independent member Finian McGrath will also attend Cabinet and have special responsibility for disability.
Frances Fitzgerald, who has been re-appointed for a second term as minister for justice, has also been named as tÃ¡naiste (deputy prime minister).


Indonesian divers may have located the flight recorders of missing AirAsia flight QZ8501, the head of the search and recovery operation has said.

Bambang Sulistoyo said he believed they had been found - and divers would try to retrieve them on Monday.
They are buried on the seabed underneath the aircraft's debris, officials say.
The possible discovery comes amid intense efforts to find the main fuselage of Flight QZ8501.
It disappeared in bad weather on 28 December with 162 people on board.
The aircraft was flying from Surabaya in Indonesia to Singapore and is lying 30m (98ft) below the surface of the Java Sea.
Three Indonesian ships had detected signals from two different locations about 3.5km (2 miles) from where the aircraft's tail was discovered, Co-ordinating Minister for Maritime Affairs Indroyono Soesilo said.
"The two are close to each other, just about 20 metres [apart],'" Mr Soesilo said. "Hopefully, they are the cockpit voice recorder and flight data recorder."
AirAsia chief executive Tony Fernandes tweeted on Sunday that he had been "led to believe" that the recorders had been found.
But Mr Fernandes said that his "main concern" was recovering bodies from the aircraft's fuselage.
Earlier he tweeted: "Let's hope today is a major breakthrough day and we can find main fuselage."
An official said earlier that a large object resembling the plane's body had been found in a sonar scan of the search area in the Java Sea.
But Supriyadi, operations co-ordinator for Indonesia's search-and-rescue agency, later told the BBC's Indonesian service that reports that the fuselage had been found had not been confirmed.
Supriyadi has said that if the main body of the plane is found, the first priority of search teams will be to remove the remains of victims.
A team of divers had been sent to investigate, he added, but up until recently poor weather conditions had once again been hampering the search efforts.
Rescue workers have been pulling bodies and wreckage from the sea but progress has been slow. At least 48 bodies have been retrieved so far.
The cause of the crash is unknown but the plane had encountered bad weather and asked for a flight path change before communication was lost.
The flight data recorders are usually housed inside the rear part of the plane.
They are designed to survive a crash and being submerged in water, and contain underwater locator beacons which emit signals for at least 30 days.
Finding them has been one of the top priorities for search teams as they provide crucial clues from the last moments of a flight before it came down.


Prime Minister David Cameron has said he expects all the parties to take part when discussions on resolving the crisis within the Northern Ireland power-sharing executive resume next week.

Talks broke up on Thursday after the Democratic Unionist leader Peter Robinson stood aside and his other party ministers, except one, resigned from the executive.
The latest crisis followed a police analysis that IRA members were involved in the murder of a former IRA man.
Three senior republicans were arrested this week and subsequently released.
Mr Cameron said he was "extremely worried" about the crisis in the Northern Ireland Executive.
"I don't think it's right for the British government to step in and suspend these institutions. I want to see the politicians of Northern Ireland ... working out how to make these institutions work," he said.
"It is unacceptable in any part of our country to have active paramilitary groups. They have to be disbanded, and disbanded on all sides."
Deputy First Minister Martin McGuinness has said there are six weeks to resolve the outstanding difficulties in the political process and said Sinn Féin was up for the job.
Speaking at a party away-day at Gormanstown, County Meath, he said the last thing the DUP wanted now was an election.
He added that he had it in his power to force a poll, but he would not do so because he wanted the six weeks to see a resolution of all outstanding problems.
Who's who
Northern Ireland Executive: The ministerial team that runs Northern Ireland's devolved government at Stormont.
It is made up of British unionist, Irish nationalist and cross-community elected representatives, set up after an historic power-sharing agreement more than 20 years ago.
The largest party in the executive is the Democratic Unionist Party (DUP), followed by Sinn Féin, the Ulster Unionist Party (UUP), the Social Democratic and Labour Party (SDLP) and the Alliance Party.
DUP and UUP: Unionist parties that want to maintain Northern Ireland's union with Britain
Sinn Féin and SDLP: Nationalist parties aspiring to a united Ireland.
Alliance Party: Neutral on the issue of the union.
The Irish Republican Army (IRA): The IRA has existed in various forms in Ireland since the early part of the 20th Century but the latest political row concerns the Provisional IRA.
The Provisional IRA was the name used by a paramilitary organisation that killed more than 1,700 people during decades of violence in Northern Ireland, known as the Troubles, which began in 1969.
The IRA declared ceasefires as part of the Northern Ireland peace process and in July 2005 it announced a formal end to its armed campaign.
During the Troubles, Sinn Féin acted as the political wing of the IRA.
A fresh round of talks to address the issue of paramilitaries and outstanding issues around welfare and Northern Ireland's budget began on Tuesday.
However, they broke down after it was revealed that Sinn Féin's northern chairman, Bobby Storey, was one of three republicans arrested in connection with the murder of ex-IRA man Kevin McGuigan Snr last month.
All three were released unconditionally on Thursday. A fourth person, a 50-year-old woman was also arrested and then released.
Following the arrests, DUP leader and First Minister Peter Robinson said his ministers would quit if the assembly was not adjourned or suspended.
Mr Robinson stepped aside on Thursday after his party failed to get enough support to adjourn the assembly.
The party's Finance Minister, Arlene Foster, now the only remaining DUP minister, has taken over as acting first minister.
"Peter Robinson had stepped aside to concentrate on leading the party delegation in the talks and he has left me there as a gate keeper and to act as first minister in his absence from that job," she said.
Addressing the McGuigan murder, Chief Constable George Hamilton said that there was no evidence at that stage that the murder was sanctioned by the IRA, which he said was committed to politics and not engaged in terrorism.
Sinn Féin's leadership has insisted that the IRA no longer exists.
Asked on a possible IRA statement as a way to overcome current problems, Sinn Féin president Gerry Adams said "P O'Neill has been decommissioned", while Mr McGuinness added "and he's not coming back".
P O'Neill was the IRA's nom de plume used to sign IRA statements throughout the Troubles.
Following the police assessment on the murder, the Ulster Unionist Party withdrew from the Northern Ireland Executive.
Northern Ireland Executive crisis: Q&A
For months the power-sharing executive at Stormont has been deadlocked over budgetary matters.
Underlying this disagreement was Sinn Féin's refusal to implement welfare reforms introduced elsewhere in the UK.
However, the political crisis deepened last month after the police said current IRA members could have been involved in the murder of Belfast man, Kevin McGuigan.
Unionists argued that if the IRA remains active, Sinn Féin should be excluded from ministerial office.
The party said it would engage in talks only if the issue of the IRA was the first item to be dealt with.
The monitoring of paramilitary activity in Northern Ireland was conducted by the Independent Monitoring Commission (IMC) up until 2011.
Ms Villiers said re-instigating an independent authority to look at decommissioning command structures was a "credible" option.
"I think it wouldn't necessarily be appropriate to set up exactly the same structure that existed in the past and certainly one would need to ask it a different question. In the past the question was just about decommissioning and ceasefires," she said.
"I think now it is very clear we want to see these paramilitary organisations disband altogether. We also want to investigate the role of members of these organisations in relation to criminality."


Environmental activist Erin Brockovich has told the BBC that failing infrastructure and weak regulation are to blame for a catastrophic gas leak in California.

The leak in Porter Ranch near Los Angeles has forced more than 13,000 people from their homes.
It began on 23 October and has been blamed for a variety of health issues.
Ms Brockovich said it was the worst environmental disaster in the US since 2010.
"This is a BP oil spill on land," she said, comparing the natural gas leak to the Deepwater Horizon explosion in the Gulf of Mexico six years ago, in which 11 people died.
The well was, she said, an "invisible volcano" spewing out gas "like lava", from the 3,600 acre Aliso Canyon underground storage facility in the Santa Susana mountains into the nearby community of Porter Ranch.
At a public meeting last week, angry residents called for the entire complex - the second-largest such facility in the US, comprising 115 wells - to be shut down.
Kelly Hill, a homeowner and landlady in Porter Ranch, was applauded as she denounced a representative of the operator and the regulators sitting alongside him.
"You are destroying people's lives," an angry Ms Hill told Jimmie Cho, senior vice president of gas operations and systems integrity with domestic supplier SoCal Gas, a division of Sempra Energy.
Thousands of people had been "chased from their homes," she said, urging Mr Cho to "shut down this decrepit, archaic facility so that all of us families in Porter Ranch can go back to our lives. Save Porter Ranch!"
The company has resisted such calls, warning that closing the entire site could imperil the Los Angeles energy supply, although it was unable to provide a figure for the proportion of the city's gas supplied by Aliso Canyon.
"We could have shortages of natural gas, blackouts for electricity, that's not something that we want to happen to the Los Angeles area," said SoCal Gas spokesman Mike Mizrahi. He denied that meant the company thought it worth the risk of leaks to keep the lights on.
"I wouldn't actually even call it a risk of leaks. We've operated this storage facility in good working order for 40 years. Safety is part of our DNA," he said.
Three months after it began though, Mr Mizrahi conceded that the firm still did not know what had caused the leak.
The company, he insisted, had complied with all relevant state and federal regulations in the run-up to the incident, although it had removed a safety valve in 1979. Some experts have argued this valve could have stopped the leak, a claim SoCal Gas denies.
At Thursday's public meeting some of the loudest cheers came when Ms Hill attacked the state regulators: the California Public Utilities Commission (CPUC), which regulates privately owned utilities, and the Division of Oil, Gas and Geothermal Resources (DOGGR), which oversees the operation of wells.
"It is obvious to all of us now that SoCal Gas is allowed to do whatever they want," she said, adding that an "incestuous relationship" between the company and its regulators must end.
According to the Governor of California, Jerry Brown, who earlier this month declared a state of emergency in Porter Ranch, CPUC and DOGGR have ordered an "independent third-party analysis" of the cause of the leak.
SoCal Gas has promised that it will be plugged by the end of February and the single well in question, a depleted oil field known as SS-25, will be taken out of use.
The use of old oil and gas wells for storing natural gas is relatively common in the United States, according to industry bodies.
SoCal Gas said the leak began when the casing around a pipe was breached at a depth of about 500ft (150m) although it was unable to say why this had happened.
Initial attempts to plug it failed. The company then drew up plans to capture and burn off the excess gas, but abandoned them amid concerns that it could lead to a catastrophic explosion.
1.77 million: approximate number of cows burping for a year to produce equivalent methane
1.41 million: number of cars that would need to be added to the road to have a similar greenhouse effect in a year
13,000: number of people who have been relocated so far
Belching cows and the LA methane leak
The firm is now drilling a relief well to a depth of about 8,500ft to reduce the pressure of the escaping gas, the roar of which can reportedly be heard up to half a mile away.
The company attributes ill effects such as nausea, nosebleeds and headaches not to the invisible natural gas itself but to a sulphurous odorant added to it to make it easier to detect a leak.
Some residents have complained of breathing difficulties as well as severe stress as they were forced to move to temporary accommodation and send their children to new schools.
About 13,000 people in 3,340 homes had been relocated, with a further 11,000 or so in 2,810 homes waiting to move, the company said.
Music producer Matt Pakucko is one of those who has moved out. Until October he worked from home just over a mile from the leaking well at the foot of the hills which rise above Porter Ranch.
He now says he can only return to the recording studio in his house when the wind is blowing the gas away.
"It's been a nightmare," said Mr Pakucko, who is the co-founder of a residents' action group, Save Porter Ranch.
Before the leak, he was already campaigning for the entire facility to be shut down, arguing that the "regulators have completely failed" to protect the community.
"This is not a Porter Ranch problem. This is a global environmental disaster," he said.
The effect of the leak on human health is contested.
SoCal Gas insists there is no evidence that it poses a long-term risk but some scientists say there are not enough data to be sure, particularly about the effect of mercaptans, which give the gas its smell, and benzene, a carcinogenic organic compound in the natural gas.
"There's concern for some of the exposures for neurodevelopment in children, for respiratory effects," said Frank Gilliland, a professor of preventive medicine at the University of Southern California's Division of Environmental and Occupational Health.
But the "most likely effect" said Prof Gilliland was "from chronic stress from the whole disaster scenario that's happenedâ€¦.for post-traumatic stress that occurs in the population."
The scientist is seeking approval to carry out research into the health effects of the leak.
The effect of the leak on the environment is a little clearer thanks to measurements of the potent greenhouse gas methane.
According to pilot and scientist Dr Steve Conley of the University of California, Davis, who has been collecting the samples on a series of flights in the area, it could account for "roughly 10% of California's total methane emissions for the year."
"As a society we need to learn the lesson from this that we need to be more ready to respond when it happens," he added.
The lawyers are now sharpening their pencils, with the possibility of a class action lawsuit bringing together thousands of claims against SoCal Gas.
Ms Brockovich, who as a consumer advocate is working with the law firm Weitz and Luxenberg, said the Porter Ranch case should raise awareness of similar problems elsewhere.
Across the country, she said, "lack of oversight, lack of inspections and lack of enforcement" was now being exposed and challenged.
"We absolutely have failing infrastructures in the oil and gas industryâ€¦ these things are corroded, they're dilapidated, they're in need of repair, they're in need of replacement, they need to be shut down and it is a problem across the United States."


Defence Secretary Philip Hammond has dismissed fresh criticism of defence cuts as "nonsense".

General Sir Richard Shirreff, the outgoing Nato deputy supreme commander, told the Sunday Times cuts to the British military had "hollowed out" the Royal Navy.
But Mr Hammond told the BBC: "We are a capable and credible ally."
Shadow defence secretary Vernon Coaker said "serious questions" remain about the planned cuts.
Sir Richard said the Royal Navy had been cut "to the bone" and left unable to take part in Nato maritime operations.
Speaking on The Andrew Marr Show, Mr Hammond said the criticism was unfounded, however.
"Nobody should be in any doubt of our resolve to live up to our commitments under the Nato treaty," he added.
The Army is undergoing a 20% reduction in regular troop numbers, from 102,000 in 2010 to 82,000 in 2020. This is to be accompanied by a rise in the number of reservists, from 24,000 to 30,000.
Over the same period, the Royal Navy and the RAF are each preparing to lose 5,000 regulars and gain 500 reservists.
Sir Richard's comments follow recent warnings about the impact of the cuts from former US Defence Secretary Robert Gates and former head of the Army Lord Dannatt.
Sir Richard warned that cutting the number of full-time troops and recruiting more reservists was "one hell of a risk".
"The point at which a risk becomes a gamble is a subjective view," he said. "I think the jury is out still."
In light of the situation in Crimea, it was necessary for Britain to "prioritise defence", he said, telling the newspaper: "A hollowed-out navy means you can't project power."
Sir Richard, who stepped down from his post last week, added it was "very noticeable" that the Royal Navy was "never participating in Nato maritime operations".
But Mr Hammond said of the criticism: "Of course I'm listening and much of what I'm hearing is nonsense.
"We still have the fourth-largest defence budget in the world.
"I was in the Pentagon just this week past. I heard my US counterpart talk about Britain as a credible, capable and reliable ally and that's what we intend to remain."
Mr Hammond stressed that savings had to be made.
"Of course we've had to take some very tough decisions," he said. "But we are working with the military chiefs to make sure that we prioritise our very large defence budget, invest it in the areas that are going to matter in the future.
"I recognise that sometimes that has meant we've had to take decisions that have upset some people about legacy capabilities but we're looking to the future, not the past."
Mr Hammond said the Navy did take part in Nato exercises and insisted it was also "busy around the world" on other operations.
These included taking part in counter-piracy missions, tackling drug traffickers and also helping in the search for the missing Malaysia Airlines plane.
"We'd like to have more assets but we are very effective at using the assets we've got to deliver the effect we need to do," he added.
Mr Coaker said: "While I agree with the rationale behind the Army 2020 proposals, serious questions remain about their deliverability.
"General Shirreff's comments signal yet another senior military voice adding to the chorus of concern over the government's defence reforms.
"The defence secretary has been too quick to dismiss these concerns and those of our allies. He has pursued his policy with little regard for the implications of its practical application."
In a statement, the Ministry of Defence said: "With a restructured, more flexible and agile army and with Â£160 billion planned on new equipment over the next decade, we will ensure our Armed Forces retain their formidable range of cutting-edge capabilities and ability to project power across the globe."


One drug can treat three deadly and neglected infections - Chagas disease, leishmaniasis and sleeping sickness - animal studies show.

It has been described as a "new hope" for tackling the parasitic infections which affect millions of people in the poorest parts of the world.
The discovery, reported in the journal Nature, was made by testing three million compounds.
The new drug is now entering safety tests before human trials.
The three diseases are all caused by similar parasites, leading scientists to believe one therapy might be useful against the trio.
Combined, the three parasites infect 20 million people and kill 50,000 each year, the research team said.
While there are some drugs to treat the infections, they are expensive and toxic and often need to be given via an intravenous drip, making them impractical in poor regions.
The researchers tested three million compounds, made by the pharmaceutical company Novartis, to find those that could kill multiple parasites in the laboratory.
One was then used as the basis of thousands of modifications to make the original 20 times more potent.
Tests then showed the upgrade - codenamed GNF6702 - could treat Trypanosoma brucei, Trypansosoma cruzi and Leishmania infections in mice.
Dr Elmarie Myburgh, one of the researchers based at the University of York, told the BBC News website: "What makes it special is the fact it is targeting all three parasites. That's the first time it has been done, so it is quite special.
"To me this is obviously a big deal, I'm in this field to try and make a difference, to get to a cure, and we're working hard in the hope that it gets to patients.
"There's been very little incentive to spend a lot of money on these diseases as they affect a very poor, and yet large, population."
Further refinements to the compound are taking place as the researchers ensure it is safe before starting human trials.
The drug works by attacking the parasites' proteasomes. The structures recycle waste proteins in the parasite.
But crucially the chemical does not affect similar processes in mammalian cells.
Richard Glynne, from the Genomics Institute of the Novartis Research Foundation, told the BBC that attacking the proteasome was "not by design, more by serendipity".
It had been thought the proteasome was too similar across all species to develop a drug that would not be toxic to the patient.
However, he said there may ultimately need to be three separate drugs: "It may be a single drug for all three diseases may not be the best strategy.
"The biology of the diseases is different. For example in sleeping sickness the parasite is in the brain, so you need a drug that gets into the brain, so there are tweaks that may be required."
Dr Stephen Caddick, the director of innovation at the Wellcome Trust research charity which helped fund the study, told the BBC News website: "These are pretty nasty, highly prevalent parasites and affect people living in the most poverty-stricken parts of world. We need to make more progress.
"We continually face challenges getting medicines to those people and making affordable medicines is an important first step.
"This is quite an important piece of research, I'm excited by it, but there's still a long way to go."
Follow James on Twitter.


Pro12 leaders Ulster will be without injured pair Charles Piutau and Franco van der Merwe for the derby against Connacht in Galway on Friday night.

Piutau suffered delayed onset concussion after last week's win over Ospreys while van der Merwe sustained an ankle ligament injury in the game.
Tommy Bowe provides a boost with the Ireland wing making his first start in six months following a knee injury.
Connacht have made six changes from the side that beat Edinburgh last Saturday.
Cian Kelleher will start on the left wing in place of the injured Matt Healy.
Peter Robb and Kieran Marmion are both sidelined with injuries so inside centre Craig Ronaldson will make his first appearance of the season following his return from long-term injury while Caolin Blade starts at scrum-half.
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Up front, hooker Dave Heffernan has been handed his first start of the campaign in the absence of the injured Tom McCartney.
With Denis Buckley ruled out, returning Ireland international Finlay Bealham comes in at loosehead.
Andrew Browne, who returns from injury, is handed his first appearance of the season and partners Ultan Dillane in the second row.
Ulster scrum-half Ruan Pienaar is rested by director of rugby Les Kiss while Callum Black comes into the front row.
Robbie Diack and Peter Browne form a new second-row partnership and Clive Ross replaces Sean Reidy at openside flanker.
Defending champions Connacht, who have only earned one win over Ulster in 20 attempts, are ninth in the standings.
Connacht: T O'Halloran; N Adeolokun, B Aki, C Ronaldson, C Kelleher; J Carty, C Blade; F Bealham, D Heffernan, C Carey, U Dillane, A Browne, E McKeon, J Heenan, J Muldoon (capt).
Replacements: S Delahunt, R Loughney, JP Cooney, L Stevenson, J Connolly, S Kerins, S O'Leary, S Ili.
Ulster: J Payne (capt); T Bowe, L Ludik, D Cave, C Gilroy; P Jackson, P Marshall; C Black, R Best, R Ah You, R Diack, P Browne, I Henderson, C Ross, R Wilson.
Replacements: R Herring, A Warwick, R Kane, K Treadwell, S Reidy, D Shanahan, B Herron, R Lyttle.


A drink driver found by another motorist lying in the road with his trousers down has been ordered to carry out 200 hours of unpaid work.

Jason Duff was discovered falling in and out of consciousness on Bo'ness Road in Polmont, Stirlingshire on 31 May last year.
The case was described by a prosecutor as one with "unusual circumstances".
The 44-year-old, of Cowdenbeath, Fife, was also banned from driving for four years.
Depute fiscal Siobhan Monks said a member of the public was driving along the road when he came across Duff's 15-year-old Peugeot 206.
Miss Monks said the Peugeot engine was running, but the vehicle was stationary, and Duff was not in it.
The other motorist stopped and found Duff "lying in the road, under the influence, with his trousers down, falling in and out of consciousness".
A blood sample taken at Forth Valley Royal Hospital three hours later showed Duff was still over twice the legal drink drive limit.
Duff told police he had drunk alcohol and slept in his car following an argument with his girlfriend.
Miss Monks said that when Duff woke up he decided to drive to work, but felt unwell, stopped his car and got out, but could remember nothing more.
Solicitor advocate Stephen Biggam, defending, said: "He had become dehydrated, that's why he passed out."
Duff pleaded guilty at Falkirk Sheriff Court to a charge of drink-driving.
In addition to the driving ban and unpaid work order, Sheriff John Mundy placed Duff under social work supervision for 18 months.
He said: "This is a serious matter.
"The court does have the power to impose a custodial sentence, but it would be better for you to receive some kind of structured support."


The Republic of Ireland beat Austria for the first time since 1963 to move top of Group D, boosting their chances of qualifying for the 2018 World Cup.

James McClean struck soon after the break with a super goal from an acute angle to surprise an Austrian team which had dominated the opening 45 minutes.
The victory, the Republic's first over Austria in nine matches, leaves Martin O'Neill's men with 10 points.
Early pace-setters Serbia drew 1-1 with Wales later on Saturday, meaning they are now two points behind the Republic, with Wales a further two points back.
Manager Martin O'Neill said before the match his team would "go for it" against a country they had beaten only twice in 14 meetings, but they failed to make an impact in a soporific first half as they were reduced to containing an Austrian side which was dominating possession.
The Republic had no shots on target in the first 45 minutes, unsurprising as they had only 35.4% of possession, and Jon Walters, leading the line on his own, had little to work with.
The Stoke forward did waste a glorious chance, shooting over the crossbar when sliding through unchallenged six yards from goal in a rare chance for the visitors.
But O'Neill's men were transformed after the break, bossing the hosts immediately.
Austria's Kevin Wimmer lost possession near his own corner flag - the Tottenham player appealed hopefully for a foul - and the visitors counter-attacked with pace.
Wes Hoolahan found McClean with a delicious pass, setting up the West Brom winger to shoot from left of goal and through the legs of Ramazan Ozcan.
Walters thought he had doubled the lead minutes later, but his header was disallowed for offside. By then however O'Neill's men had done enough to record a historic win.
Austria, many people's dark horses before the start of Euro 2016 after their impressive unbeaten qualifying campaign, have struggled to stop the rot which set in in France, when they went out in the group stages.
They have now won only once in seven games and are six points adrift of a Republic side who are top after four of their 10 qualifying games.
Their star players - Bayern Munich's David Alaba and Stoke's Marko Arnautovic - failed to inspire and the odds on Marcel Koller's side qualifying for their first World Cup since 1998 have lengthened.
Austria had chances, their best coming just before the break when Marcel Sabitzer struck the crossbar after being put through by Arnautovic.
But the player which summed up their disappointing 90 minutes was Marc Janko, who twice squandered chances to level. The striker should have at least tested Darren Randolph instead of heading wide and did the same in injury time in what was his team's last throw of the dice.
Republic of Ireland boss Martin O'Neill: "Austria will naturally be disappointed because they have dropped all three points here, they drew at home with Wales and were beaten by Serbia.
"Something tells me that they still have a chance and while I believe - and have always believed - this group will be tight, I think teams will still take points from each other.
"I'm really pleased to have 10 points on the board from four matches. But there are a million miles to go."
Austria manager Marcel Koller: "It is very difficult for us and they are big points for Ireland, who are well ahead of us now and will take a lot of self-confidence into the winter break.
"But there are still six games and 18 points to play for. I know it will be difficult, but we will do everything we can to be successful.
"We knew Ireland played a very defensive game and, after going in front, they became even more defensive. But if you do not score, then you do not win the game."
Martin O'Neill's men host Wales in Dublin on 24 March, but will be without Robbie Brady who will be suspended for the match after receiving a yellow card in this match. Austria, meanwhile, play bottom-of-the-table Moldova on the same day.


A two month public consultation has begun on plans to build a giant offshore wind farm in the Irish Sea.

Celtic Array, a joint venture between Centrica and Danish company Dong Energy, plans to build between 150 and 450 turbines by the end of the decade.
The Rhiannon wind farm would be situated about 12 miles (19km) north-east of Anglesey and about 21 miles (34km) from the Isle of Man.
A company spokesman said the public consultation will run until 19 May.
The Rhiannon wind farm is one of a dozen sites around the UK where offshore wind farms could be built in the next 10 years.
First announced in January 2010, the project could generate up to 2.2 GW of electricity, or enough to meet the needs of around 1.7 million homes.
Two years of assessment have already been completed to establish the physical, environmental and engineering constraints of building out in the Irish Sea.
If the planning inspectorate gives permission, construction could start as early as 2017.
Among the proposals are a new overhead power connection across Anglesey and the Menai Strait, maximising use of existing network on the mainland, and replacing three underground cables in the Glaslyn estuary with 12.


A 22-year-old woman from Mexico's Tarahumara indigenous community has won a 50km (31 miles) ultramarathon wearing sandals.

María Lorena Ramírez defeated 500 other runners from 12 countries in the female category of the Ultra Trail Cerro Rojo in Puebla, in central Mexico.
She ran without any professional gear, and her pair of sandals was reportedly made from recycled tyre rubber.
The Tarahumara are famous for being excellent runners.
The race was held on 29 April, but only now has word about her victory spread.
Apart from the sandals, she wore a skirt and a scarf in the race. The runner did not have any professional training.
She finished the race at seven hours and three minutes, and was awarded 6,000 pesos ($320; £250).
Reports said her job is herding goats and cattle, walking some 10-15km every day.
Last year, she came second in the 100km category of the Caballo Blanco ultramarathon, in Chihuahua.


Two NHS officials whose pay rises were reviewed as part of a government investigation of their clinical commissioning group have resigned.

Liverpool Clinical Commissioning Group's (CCG) chief officer Katherine Sheerin and chief finance officer Tom Jackson have both left their posts.
In June, the CCG's deputy chairwoman Prof Maureen Williams quit after a committee she chaired was criticised for making decisions on pay increases.
The CCG has made no further comment.
Ms Sheerin, who has worked for the CCG for five years, said after 25 years in Liverpool, she had "decided it is the right time to move on", while Mr Jackson said that following his colleague's resignation, "I too have decided to stand down".
The government ordered a review into the CCG in March after Rosie Cooper, the Labour MP for West Lancashire, raised concerns about pay increases for governing body members between 2013-14 and 2014-15.
Most of the pay rises related to the 2014-15 financial year, when chairman Dr Nadim Fazlani's salary rose from approximately Â£105,000 to Â£155,000.
The review said the remuneration committee, of which Prof Williams was chairwoman, had "acted outside its terms of reference" by making decisions on pay increases, rather than making recommendations.
It also highlighted conflicts of interest, particularly in the CCG's first year of operation in 2013-14, which "were not managed robustly with a lack of independent advice and scrutiny of decisions".


A devastating tropical disease should be eradicated within three years, says the former American president leading the fight against it.

There were 3.5 million cases of guinea worm worldwide when Jimmy Carter's organisation started tackling the disease in 1986.
Now there are just 126 cases globally - many of them in South Sudan and Mali.
Mr Carter acknowledged that Ebola had diverted some resources - but said this was "only proper".
Eradication of guinea worm would make it the first human disease to have been wiped out since smallpox - and the first to be eliminated without a vaccine or medicine.
The highly debilitating infection comes from a parasite and is spread by drinking contaminated water.
Mr Carter told me: "It's hard to get our people and vehicles into South Sudan and Mali, because of the conflict in both those countries.
"But we're making good progress there, as well as in Chad and Ethiopia, where the remaining cases are.
"It's impossible to determine exactly when we'll do away with it - but I think it will be in the next two or three years at the latest.
"Once the disease begins, you can't do anything about it until the worm comes out of the human body.
"That takes about a month, because the worm is about a metre long. It's a horrible disease, a terrible affliction."
The organisation he founded, the Carter Center, has visited all 26,300 villages - mostly in sub-Saharan Africa - which have had guinea worm, to train people in dealing with it and preventing it.
The former president added: "Once the water is contaminated, if people don't use a proper filter cloth for every drink, the disease can come out of that pond of filthy water again.
"So we have to monitor villages even if they didn't have a case last year, because they might have a case this year.
"You have to be constantly vigilant.
"There's no doubt Ebola has taken away some effort from fighting guinea worm in Mali - but it's very proper that people have concentrated on Ebola."
He said efforts to tackle other health conditions had been temporarily diverted to focus on Ebola.
"We've trained 144 psychiatric nurses in Liberia - because there have been terrible problems in that country with mental health.
"Their work has been diverted into helping fight Ebola, but they'll go back to their psychiatric work now.
"The crisis needed to be met and we were glad to turn those nurses loose to work on Ebola."
Mr Carter's team is also tackling river blindness, another terrible parasitic disease which causes sight loss and skin problems.
It results in itching which is so hard to endure that some sufferers take their own lives.
The transmission of river blindness has been stopped in Colombia, Ecuador, Guatemala and Mexico - but the disease is still endemic in more than 30 countries in Africa and Latin America.
Drug treatment exists and many free doses have been supplied by the manufacturer Merck, but eradication is further away than with guinea worm.
Mr Carter said: "The policy has traditionally been to control the disease and prevent blindness by targeting the microscopic worms.
"But the adult worms would remain in the body and still need treating year after year.
"The Carter Center began an experiment in Latin America. We found that treating the disease more than once a year meant you could actually eliminate it.
"We alone will treat around 25 million people for river blindness this year.
"We've proven in Latin America, as well as Sudan and Uganda, that the disease can be completely eliminated.
"And it gives people in Africa who've suffered so long with these diseases an element of confidence, self-respect and hope for the future."
Mr Carter, who turned 90 in October, added: "I've been blessed with good health, and I still enjoy going out to these countries and leading the work. I'm still going strong!"
Last week, Mr Carter sent the manuscript for his 29th book to his publisher.
It is about the lessons he has learned from his life - and includes reflections on his marriage, race relations in America and his 11 years as a submarine officer with the US Navy.


The chances of seeing the Aurora Borealis from the UK could be decreasing and even disappear altogether, say scientists.

Scotland is one of the best places in the UK to observe the Northern Lights, which are related to activity on the sun.
Scientists at the University of Reading suggest this activity could be falling to its lowest in 300 years.
They said this would mean the aurora being confined to the North Pole.
Activity on the sun is cyclical and scientists say it is currently headed to the period of lowest activity in the cycle called the solar minimum.
The Aurora Borealis is caused by the interaction of the solar wind - a stream of charged particles escaping the sun - and Earth's magnetic field and atmosphere.
The Northern and Western isles, the Highlands and north east Scotland offer some of the best places to observe the Northern Lights at night when skies are clear.
Aberdeen's associations with the Aurora Borealis are celebrated in the local song, The Northern Lights of Old Aberdeen.
In the past, the city's tourist information staff have been asked when the "lights were turned on" by visitors unsure of what causes the displays.
If you have been lucky enough to see the Northern Lights you won't need to be told how awe inspiring the displays can be.
Growing up in deepest rural Aberdeenshire my mum would often tell me at breakfast how wonderful the aurora had been the night before.
"Why didn't you wake me up?" I'd whine, only to be told the "lights" had "come on" well after my bed-time.
When eventually I was old enough to be up a bit later and caught sight of the aurora I found myself riveted to the spot.
It was on a cold night and the temperature was below freezing, but I didn't notice the cold. I was transfixed by a giant curtain of light, being tugged into rippling movement by a silent wind and of colours that changed from bright green to deep purple.
I stood staring up at the Northern Lights until my hands were blue with cold and my neck ached...and my mum had shouted at me for the umpteenth time it was time to come inside.
Reading University's Dr Mathew Owens, whose study of the aurora with Prof Mike Lockwood has been published in the journal Scientific Reports, said activity on the sun was reducing.
He said: "The magnetic activity of the sun ebbs and flows in predictable cycles, but there is also evidence that it is due to plummet, possibly by the largest amount for 300 years.
"If so, the Northern Lights phenomenon would become a natural show exclusive to the polar regions, due to a lack of solar wind forces that often make it visible at lower latitudes."
Scientists have been observing the decline in activity on the sun for some time.
Towards the end of last year, Nasa's Solar Dynamics Observatory spacecraft recorded Earth's nearest star hitting its lowest level of solar activity since 2011.
The Solar Dynamics Observatory captured an image of the sun showing it almost completely clear of sunspots, indicators of activity on the star.


(Close): Wall Street finished lower on Tuesday as oil prices slipped, leading investors to worry about banks' exposure to the energy sector.

The Dow Jones industrial average fell 188 points, or 1.1%, to 16,431 points.
The S&P 500 lost 1.3%, or 24.2 points, to 1,921.29 points, while the Nasdaq composite fell 1.5% to 4,503.1 points.
Oil prices fell again, with US crude down 4.6% to $31.87 a barrel and Brent crude dropped to $33.27.
Shares in Dow Jones member JP Morgan fell 4.3% after the bank said it would set aside an extra $500m to cover losses from loans to oil and gas companies.
Bank of America slid 3%, while Citigroup dropped 3.4%.
Energy shares were also hit. Chevron fell 4.4%, while Halliburton and Baker Hughes both slipped more than 2%.
Traders said investors remained cautious, with trading volumes far lighter on days the market has risen and heavier on days it has fallen.
That suggested that there was more interest among investors in selling shares rather than buying them.
Ryan Larson, head of US equity trading at RBC Global Asset Management, said: "We aren't seeing the buying interest that you would usually see in a major upward swing in the markets. Although we have come off the bottom, it's still quite volatile out there."


An ITV journalist has described how he tried in vain to save the life of an elderly man who drove his car off a harbour wall in Greece.

Tom Bradby described in a series of tweets how he dived in after the man but "couldn't get him out".
The father-of-three, who was in Rafina on a family holiday, said he believed the man had committed suicide.
The Rafina Port Authority in Greece confirmed a man had died after his car went off the wall.
A spokeswoman said the incident happened at about 16:30 local time, but would give no further details.
Mr Bradby, who is ITV's political editor, said he was "shaking with shock and anger" after complaining that officials nearby did not do more to help.
He claimed that of the nine or 10 officials on the quay, one went in to try to get the driver out as the car sank, and "the rest watched".
Bradby, 48, has been announced as the new host of ITV's News at Ten.
He was previously a royal correspondent, and secured the first official interview with the Duke and Duchess of Cambridge after their engagement.


Former Sri Lanka captain Kumar Sangakkara has signed a new one-year contract with Surrey.

The 38-year-old batsman scored 1,039 runs at an average of 49.47 in the County Championship this season.
Sangakkara also scored 278 runs in seven innings in the One-Day Cup as Surrey reached the final, and 228 runs in eight T20 Blast appearances.
"Nice to have the King back again," Surrey head coach Michael di Venuto posted on Twitter.


Gold medal weightlifter Catrin Jones has opened a £125,000 extension at the Holyhead and Anglesey weightlifting and fitness centre.

The facility has already helped groom 100 national and one world champion as well as Commonwealth Games medallists.
Ms Jones, 18, from Bangor, Gwynedd, recently brought back a gold medal from the Youth Commonwealth Games in Apia, Samoa.
The grant-funded extension has new physiotherapy and activity areas.