DAMASCUS - Russian President Vladimir Putin on Wednesday demanded "convincing" proof that ally Syria used chemical weapons, even as he softened his tone towards the West ahead of this week's G20 summit.
Putin's comments came as US lawmakers began rallying behind President Barack Obama's plan to launch military strikes against Syria over a suspected poison gas attack outside Damascus that killed hundreds last month.
As Obama seeks to cobble together an international coalition to back his plans for military intervention, France was Wednesday to hold an emergency parliamentary debate from 1400 GMT on the Syrian crisis.
Putin, in an interview apparently aimed at presenting a more pragmatic face to the world ahead of the G20 summit in Saint Petersburg, said he did not exclude Russia agreeing to US-led military strikes if it was proven Syria's regime had carried out the August 21 attack.
But, he told state-run Channel One television, the West still needed to put forward watertight proof of the circumstances of the attack.
"If there is evidence that chemical weapons were used, and by the regular army... then this evidence must be presented to the UN Security Council. And it must be convincing," Putin said.
If there was clear proof of what weapons were used and who used them, Russia "will be ready to act in the most decisive and serious way," he added.
He stressed that it would be unacceptable for the West to go ahead with military action against the regime of Bashar al-Assad without the assent of the UN Security Council, where Russia has veto-wielding permanent membership.