Syria: EU says there is 'strong evidence' Assad behind chemical attack but urges world to wait for UN report before launching strikes EU leaders meeting with U.S. Secretary of State John Kerry cite 'strong evidence that the Syrian regime is responsible' for chemical attacks Sarin gas strikes on areas around Damascus on August 21 may have resulted in deaths of more than 1,400 people says U.S. UK International Development Secretary Justine Greening urges countries to step up humanitarian aid Britain pledged £52million extra aid to help £1.9billion UN shortfall European Union ministers ended days of division today by agreeing Syrian president Assad's regime was likely to be behind recent chemical attacks outside Damascus that may have killed more than 1,400 people. But the 28 EU nations said any potential military attack against Assad's regime should hold off until the results of a U.N. inspectors' report are released. U.S. Secretary of State John Kerry, who met with EU leaders in Vilnius, Lithuania, said he welcomed this 'strong statement' backing all 'the efforts to hold the Assad regime accountable for what it has done'. Agreement: U.S. Ambassador to Lithuania Deborah McCarthy (left), US Secretary of State John Kerry (second left), Lithuanian President Dalia Grybauskaite (second right) and Lithuanian Minister of National Defense Juozas Olekas (right) at the presidential Palace in Vilnius 'Step up': UK International Development secretary Justine Greening has urged UN nations to send more humanitarian aid EU ministers said available intelligence 'seems to indicate strong evidence that the Syrian regime is responsible for these attacks' and underlined 'the need to move forward with addressing the Syrian crisis through the U.N. process' - but did not back any military intervention at present. Earlier today, UK International Development Secretary Justine Greening said countries should do more to supply humanitarian aid in the absence of any military response. With the United Nations not even half way to meeting its funding target to deal with the fallout - which has created two million refugees - the Conservative minister said it was time for states to 'step up' their contributions. The decision 'does not need to wait' until after any US-led strikes against the regime, she said. Ms Greening said the UK - already the second most generous donor - had 'always planned' to take a leading role and was not seeking to up its contribution as a result of the Commons vote against British involvement in military action British Prime Minister David Cameron welcomed offers of new humanitarian assistance for Syria from Canada, Italy and Qatar at the G20 summit, following his announcement of an additional £52million in British aid. He said he wanted to 'set the drumbeat' of momentum towards filling a £1.9billion shortfall in UN funds to assist millions of people affected by the two-and-a-half year civil war. It is believed that the UN inspectors' interim report to Secretary-General Ban Ki-moon will contain details on the gas, ammunition and delivery systems used in the attack that killed hundreds of people in a suburb of Damascus. Horrific: A Syrian man mourns over the bodies of victims of the August 21 gas attack on and around the city of Damascus Lithuanian Foreign Minister Linas Linkevicius, who hosted the meeting, spoke of 'more and more evidence that the Assad regime is behind all these crimes', adding: 'We just can't ignore this.' The EU ministers welcomed French President Francois Hollande's statement that leaders should wait for the result of the UN report before launching an attack, even though France had said the report would only show an attack had taken place and not apportion blame. The EU also stressed that perpetrators for such chemical attacks should face possible prosecution by the International Criminal Court in The Hague. Germany, the only EU member of the G20 summit not to co-sign a joint statement assigning blame to Assad's regime that was issued in St Petersburg on Friday, joined in blaming the attack on the Syrian government. 'Strong statement': The U.S. Secretary of State welcomed the agreement by the EU that Assad was likely to be behind sarin gas attacks A senior U.S. State Department official who attended Kerry's meeting with the ministers said Kerry made clear that the U.S. has not made any decision to wait. The U.S. blames Assad's regime for the chemical attack and, citing intelligence reports, says sarin gas was used. The U.S. says 1,429 people died, including 426 children. The Britain-based Syrian Observatory for Human Rights, which collects information from a network of anti-regime activists, says it has only been able to confirm 502 dead.