'Samples contained sarin gas'

The United States has proof that sarin gas was used in a Damascus attack, Secretary of State John Kerry said yesterday, as he urged Congress to vote for military action against the Syrian regime.

Hair and blood samples given to the US by emergency workers on the scene of last month's attack have showed signs of the powerful sarin nerve gas, Kerry told NBC and CNN television.

Citing what he called "a very important development", he said:

"In the last 24 hours, we have learned, through samples that were provided to the US and have now been tested, (that) hair samples and blood samples have tested positive for signatures of sarin," Kerry told NBC's Meet the Press.

"Each day that goes by, this case is even stronger. We know that the regime ordered this attack. We know they prepared for it. We know where the rockets came from. We know where they landed," he added on CNN.

"We know the damage that was done afterwards. We've seen the horrific scene all over the social media and we have evidence of it in other ways, and we know that the regime later tried to cover up."

Kerry blitzed Sunday morning television talk shows to relaunch his bid to build a case for US military strikes after President Barack Obama called on Congress to authorise action.

He urged his former colleagues in Congress to give Obama a green-light for strikes against the regime of President Bashar al-Assad.

In a huge political gamble, Obama has committed the fate of US action to lawmakers, so lifting the threat of immediate strikes.

The move followed last week's defeat of Britain's Prime Minister David Cameron in the House of Commons when members voted against participation by Britain in any strike on Syria.

Obama said he had decided the August 21 chemical weapons attack on a Damascus suburb - that Washington says killed more than 1400 people - was so heinous he would respond with a limited US military strike.

But, in a move which could reshape the balance of power between Capitol Hill and the presidency, he said he believed it was important to secure support from Congress to wage war.

Obama will be fairly confident of winning the vote in a Senate controlled by Democrats and including several Republicans, such as Senator John McCain, who have called for military action against Syria.

But it would be risky to predict how the vote might go in the Republican-controlled House of Representatives, which will debate Syria as soon as it comes back into session on September 9.

Yesterday Syria hailed an "historic American retreat" in response to Obama's delay and as Obama appeared to step back from the brink, France said it could not act alone in punishing President Bashar al-Assad, making it the last top Western ally to hesitate about bombing Syria.

Syria's opposition coalition yesterday called on the US congress to okay military action, saying any action should be accompanied by more arms for the rebels. - Sapa-AFP, Reuters