WASHINGTON (CNN) -- Secretary of State John Kerry heads to Geneva on Thursday for a high-stakes meeting with his Russian counterpart that could conceivably tip the balance on whether the United States strikes Syria militarily over alleged chemical weapons use.
Separately, sources said U.N. chemical weapons inspectors are expected to deliver their report next week -- as early as Monday or Tuesday -- to the Security Council about the specific incident that is fueling the standoff with the United States -- an August 21 sarin gas attack the Obama administration says killed more than 1,400 people and blames on the Syrian government.
The regime of Bashar al-Assad denies it gassed its own people outside Damascus in violation of a longstanding global ban on chemical weapons use in what President Barack Obama calls a moral abomination that he believes Americans and the international community simply should not tolerate.
As part of a surprising diplomatic surge that has sidelined Obama's drive to win public and congressional support for military strikes to punish the Syrian regime, Kerry will hold two days of meetings in Geneva with Russian Foreign Minister Sergey Lavrov.
The pair will discuss the specifics of Moscow's plan that would put Syria's chemical stockpiles under international control, described as a difficult but momentous step that would nullify the threat of weapons of mass destruction and diffuse the crisis without any U.S. military intervention.
In his address to the nation on Tuesday, Obama said he was willing to test the seriousness and feasibility of the proposal before resuming his push for congressional authorization for military action, which at the moment appears to be an unlikely prospect.
Kerry will take the lead in dealing with the Russians, Obama said.
"It's too early to tell whether this offer will succeed and any agreement must verify that the Assad regime keeps its commitments," Obama said in his prime-time speech to a war-weary public that is skeptical of another military venture in the Middle East.
"But this initiative has the potential to remove the threat of chemical weapons without the use of force, particularly because Russia is one of Assad's strongest allies," he added.
'Verifiable process' required
Kerry and Lavrov talked by phone Wednesday about their "shared objective of having a substantive discussion about the mechanics of identifying, verifying and ultimately destroying Assad's chemical weapons," a senior State Department official said.
Russian officials have submitted a plan to the United States, Russia's Itar-Tass news agency reported Wednesday, citing a Russian diplomatic source.
White House spokesman Jay Carney said that conversations took place and papers exchanged with Russia, but that he was unaware of a full formal proposal.
"I think we're not at the stage of putting down public pieces of paper," he said.
Vladimir Chizhov, Russia's emissary to the European Union, explained that the plan calls for Syria's chemical weapons to be placed under international supervision -- inside that country initially, at least.
"The ultimate aim is to have these weapons destroyed," Chizhov told CNN's Christiane Amanpour.
He acknowledged the task of gaining control of the weapons and destroying them with civil war raging in Syria won't be easy, voicing worries about what rebel fighters might do.
Separately, the United States, France, and Britain discussed a U.N. Security Council draft resolution, according to a spokesman for British Prime Minister David Cameron.
The council -- comprised of permanent members the United States, China, France, Britain and Russia -- were scheduled to meet on Wednesday, a U.N. diplomat said.
Administration officials have not disclosed how long the window for a diplomatic solution will remain open.
How long window open?
But Sen. Dick Durbin said following Obama's meeting this week with Senate Democrats that the president asked asked lawmakers "for some time to work things out -- a matter of days into next week." Though another Senate Democrat said it could take weeks.
Carney said "it obviously will take some time" to assess if there is tangible progress.
Members of Congress will watch Kerry's trip closely for a sense of Obama's next move following weeks of beating the drum for military action against Syria.
"If diplomacy fails, he's painted himself into a corner," Sen. Lindsey Graham told CNN after Obama's speech. "The leader of the free world can't say all these things at the end of the day and do nothing."
Senior State Department officials have cautioned that negotiations over the proposed deal may not conclude after the scheduled round of talks in Geneva. The plan would be to take any final deal to the United Nations Security Council to be formalized in a resolution.
Outcome far from certain
While Obama has asked Congress to hold off for the moment on considering a military strike, he did say that he had ordered the armed forces to maintain its posture in the region "to keep the pressure on Assad."
Obama has said the operation would be targeted, limited and not involve U.S. ground forces. The goal would be to degrade al-Assad's ability to use chemical weapons.
The path to any vote in the Security Council remains far from certain. Russian President Vladimir Putin has said that any action there with the looming threat of military action could result in a Russian veto.
Analysts say Kerry has his work cut out for him.
"I think it's unlikely the Russian government is going to relent on this issue of whether or not it would support the use of force in a security council resolution," Nicholas Burns, a former senior State Department official now at Harvard University's Kennedy School of Government told CNN.
"They've been consistent since day one of the Syrian crisis that they did not want to see the United States or anyone else use force. I think that's one of the ambitions the Russians have going into this negotiation in Geneva," he added.
Former Secretary of State Madeleine Albright said in an exclusive interview on CNN's "The Lead with Jake Tapper" that Kerry must not take the threat of force off the table in his talks with the Russians even if they insist he drop it.
"This is the way that diplomacy works. You use the threat of the use of force to get some action in diplomacy, and then diplomacy just to figure out what you do about the threat of the use of force," said Albright, who served as America's top diplomat under President Bill Clinton.
"One of the things I know from trying to get Security Council resolutions is that they take a while," said Albright. "But my personal feeling here is that it is that threat of the use of force, and the president made very clear that our ships would stay in the area, and that the use of force would stay on the table."
Elise Labott, Barbara Starr, Greg Bothello, John King, Jake Tapper and Dana Bash contributed to this report.