"I challenge those who accuse our forces of using these weapons to come forward with the evidence," said Syrian Foreign Minister Walid Muallem.
He accused US Secretary of State John Kerry of lying when he stated there was "undeniable" evidence of a large-scale chemical attack launched by Damascus.
He insisted that Syria will not submit quietly to an attack.
"We have two options - either surrender or defend ourselves," said Mr Muallem.
"The second choice is the best. We will defend ourselves."
The government said that Mr Kerry had "fabricated" evidence when he accused Syria of non-cooperation with UN inspectors and delaying their arrival to the sites, blaming rebels for a sniper attack on their convoy in disputed territory.
The Arab League also blamed the Syrian government for the attack, calling on UN security council members to agree on "deterrent" measures against those who committed the "heinous crime."
Russian President Vladimir Putin warned against precipitate action. It is likely that Russia and China will block US efforts to authorise action through the UN security council.
But, with Britain building up air force reserves in the area and US Defence Secretary Chuck Hagel declaring that the US had "moved assets in place to be able to fulfil ... whatever option the president wishes to take" it appeared that the West was set on a collision course with Syria, security council decision or not.
However other countries were not so bloody-minded.
Italy insisted that any military strike against Syria must be authorised by the security council.
Foreign Minister Emma Bonino called the chemical attack a "war crime," but said the government wouldn't support military action without security council authorisation, as the body was "the only point of legal reference."