Secretary of State John Kerry says the US has evidence that the chemical nerve agent sarin nerve gas was used in a deadly 21 August chemical attack near Damascus.
Mr Kerry made the disclosure in a series of television interviews a day after President Barack Obama delayed imminent military action in Syria to seek approval first from the US Congress – a decision that puts any strike on hold for at least nine days. He said samples from hair and blood gathered after the attack “tested positive for signatures of sarin”.
UN experts have been in Syria gathering evidence to determine whether chemical weapons attacks have taken place on various occasions. They have now arrived in the Netherlands with samples for analysis. Mr Kerry implied that the US evidence was supplied by its own sources, rather than via the UN inspectors.
Mr Kerry declined to say whether Mr Obama would go ahead with military action if Congress rejects the president’s request. Congress is due to reconvene on 9 September, meaning any military operation would not happen until then.