Syria promised to renounce chemical weapons Tuesday as diplomatic wrangling between Russia and Western powers again pushed back the threat of US strikes against the regime.
Bashar al-Assad's regime, seizing on a plan by its Russian ally for its nerve gas arsenal to be taken under international control, said it would sign the UN treaty banning chemical arms.
Damascus' offer came as US President Barack Obama stepped up his battle to secure domestic public and Congressional support for punitive missile strikes against the regime.
Meanwhile envoys from Britain, France and the United States met at the United Nations to draft a resolution to permit enforcement action if Syria fails to give up the arms.
But Russia, despite having floated the disarmament plan itself on Monday, denounced the motion, and President Vladimir Putin said Washington must drop its planned strikes.
Western capitals are deeply skeptical that Assad, locked in a two-and-a-half-year civil war, will give up his deadly chemical arsenal without at least the threat of action.
But his foreign minister, Walid al-Muallem, insisted he was serious.
"We are ready to state where the chemical weapons are, to halt production of chemical weapons and show these installations to representatives of Russia, other countries and the UN," he told Russia's Interfax news agency.
"We want to join the chemical weapons ban treaty. We will respect our commitments in relation to the treaty, including providing information on these weapons."
Syria is one of only seven UN member states not already party to the 1993 "Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction."
Signatories are supposed to destroy any chemical weapons under their control and to allow UN inspectors access to their sites.
On August 21, according to US intelligence, Assad's forces fired a volley of rockets loaded with sarin gas at several rebel-held Damascus suburbs, killing 1,400 people.
Obama argues that a long-standing international taboo was breached and, along with a small coalition of allies including France, vowed to punish the regime.
This drew an angry response from Russia, which has long provided Assad with diplomatic cover, but on Monday even Moscow proposed that Syria put its arms beyond use.
Putin, Assad's most powerful foreign ally, said the Syrian offer could end the crisis, but only if the United States withdraws its threat to take punitive action.
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"It all makes sense and can work if the US side and all those who support it renounce the use of force," Putin said, according to Russian television.
"It is difficult to constrain Syria or another country to disarm unilaterally while military action against that country is being prepared."
Russia's intervention has further complicated Obama's already difficult battle to win domestic support for a plan for limited US missile strikes against Syrian targets.
The US administration's big hitters were again in front of Congressional committees Tuesday to defend the mission, and Obama was himself to make a major televised address in the evening.
Secretary of State John Kerry, taking part in an online discussion hosted by Google+, urged Assad to seize the chance for peace.
"Help us in the next days working with Russia to work out the formula by which those weapons can be transferred to international control and destroyed," he pleaded.
A US official said Kerry would travel to Geneva on Thursday to discuss the crisis with his Russian counterpart Sergei Lavrov.
Kerry said he had already discussed Russia's disarmament plan with Lavrov by telephone and, while Washington remains cautious, he said he found the ideas interesting.
"If we can in fact secure all of the chemical weapons in Syria through this method, clearly that's by far the most preferable, and would be a very significant achievement," he said.
Washington's allies France and Britain said they were drawing up a tough UN resolution that would authorize enforcement action if Syria failed to hand over its weapons.
"It will provide for extremely serious consequences in the event of Syria violating its obligations," French Foreign Minister Laurent Fabius said.
Britain's Prime Minister David Cameron said it would contain strict timetables.
"This is not about... monitoring chemical weapons in Syria. It's got to be about handing them over to international control and their destruction," he said.
And Kerry insisted: "We need a full resolution from the Security Council in order to have the confidence that this has the force that it ought to have."
The crisis flared when Assad's forces launched a brutal crackdown on anti-regime protests in March 2011, and spiralled into a civil war that has killed more than 100,000 people.