Updated

British Foreign Secretary William Hague on Saturday welcomed a US-Russian deal to eliminate Syria's chemical weapons and said the priority now was the "full and prompt implementation" of the agreement.

Hague said the ambitious deal, struck between US Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov in Geneva, was a "significant step forward" and the onus was now on Syrian President Bashar al-Assad to comply.

"Have spoken to Secretary Kerry. UK welcomes US-Russia agreement on #Syria chemical weapons. Urgent work on implementation now to take place," Hague said on Twitter.

In a fuller message issued by the Foreign Office, he said: "The priority must now be full and prompt implementation of the agreement, to ensure the transfer of Syria's chemical weapons to international control.

"I will hold talks with Secretary Kerry and (French) Foreign Minister (Laurent) Fabius in Paris on Monday to discuss the way forward, including action at the United Nations Security Council.

"The onus is now on the Assad regime to comply with this agreement in full. The international community, including Russia, must hold the regime to account.

"This includes doing everything we can to stop the continuing bloodshed in Syria, bringing all sides together to agree a political solution to the conflict."

Britain has been pushing for a strong international response to an alleged chemical attack in Damascus last month which was blamed on President Bashar al-Assad's regime.

But Prime Minister David Cameron was forced to back down on threats of military action, made alongside the United States, after lawmakers voted against strikes.