Russia will send the United States details of its proposal to secure Syria's chemical weapons stockpile later Tuesday, US Secretary of State John Kerry said.
The details would come during the "course of the day," Kerry said, shortly after talking with Russian Foreign Minister Sergei Lavrov by telephone.
But he insisted that any plan must lay out "consequences" if it turns out to be a delaying tactic to avoid US military action.
The regime of Syrian President Bashar al-Assad is accused of using chemical weapons in an August attack near Damascus, which Washington says killed 1,400 people.
Russia has proposed that Syria's chemical weapons stock could be brought under international control in a bid to head off threatened US military strikes.
Lavrov "had some interesting observations about the ways in which he thinks we might be able to achieve this," Kerry said, speaking at an online forum organized on Google+.
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"He is sending those to us. They'll be coming in formally during the course of the day. We'll have an opportunity to review them.
"If we can in fact secure all of the chemical weapons in the Syria, through this method, clearly that's by far the most preferable, and would be a very significant achievement," he said.
But Kerry stressed the proposals must be an "ongoing verifiable process" with full international access to all of the sites in question.
"This cannot be a game. And that we have made very, very clear to the Russians," he said, voicing skepticism whether the proposals can be implemented.
The US, France and Britain are working on a resolution to go before the United Nations.
"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," Kerry insisted.
"Common sense tells us that we don't want to buy into something that isn't going to get the job done. So this has to be transparent, accountable, fully implementable and a clearly verifiable process and we're going to have to work at how that's going to be achieved," the top US diplomat said.
"But it's also going to have consequences if games are played or somebody tries to undermine this. And I think the whole world needs to invest in that."