During a 14-minute conversation that had been previously scheduled, the Russian foreign minister said he would speak out about the issue but played down the idea that a proposal was on the table, the official said.
Kerry told Lavrov that the United States "is not going to 'play games,'" the official said. "If there is a serious proposal, we will take a look."
Could 'goof' be solution?
The comments from Kerry and counterparts in Russia and Syria are the latest twist in an international crisis that has also become a fierce political battle in the United States.
The Obama administration says the al-Assad government was behind an August 21 chemical weapons attack outside Damascus. And the U.S. president is seeking congressional approval for a military strike in response.
So far he's met resistance from lawmakers and the public who are concerned about the United States again intervening militarily in a foreign crisis.
On Monday, Harf said looking at the Russian proposal doesn't mean the White House is backing down from its push to get authorization to strike Syria.
"In fact, the opposite. .... We think this is why it's even more important that Congress votes to authorize the president to use military action against Syrian regime targets, because we can be clear that if we don't give authorization to do so and we don't respond, then Assad will see that as a green light to continue using these chemical weapons."
But could Kerry's possible gaffe be the key to a diplomatic solution?
Commentator Andrew Sullivan says he hopes so.
"We have the possibility of two things: that Russia might actually act decisively to rein Assad in, and also support the only viable policy to accomplish what Obama wants -- protecting the world from these vile weapons," Sullivan wrote Monday. "I have no idea whether this is a serious move by Lavrov -- but it sure seems so, and it presents a fascinating non-binary option. ... Sometimes, it seems, Kerry's incompetence strikes gold. Here's hoping."
Whatever happens, the prospect of a diplomatic deal is likely going to make the Obama administration's attempts to make a case before Congress even more difficult, said Michael O'Hanlon, a senior fellow at the Brookings Institution. Lawmakers who are already debating whether or not to pass resolutions authorizing military action now may want to rewrite them, he said.
"It's going to obviously throw a monkey wrench in the gears on a number of things," he said.
There's already been at least one delay.
Senate Majority Leader Harry Reid is holding off on taking steps toward a first vote. An aide said that the Russia proposal is serious and fluid enough that members do not want to lock themselves into a position on Syria just yet.
An initial Senate vote on whether to authorize a military strike against Syria had been expected on Wednesday.
Reaction in the United States, beyond
French Foreign Minister Laurent Fabius said the Russian proposal "deserves a thorough examination."
It would be acceptable under several conditions, Fabius said. Al-Assad should immediately hand over control of the weapons and allow their destruction, he said, calling for the U.N. Security Council to pass a binding resolution with "firm consequences."
"Since the beginning, France has set two goals: punishment and deterrence," he said. "That is why we are now asking specific, rapid and verifiable commitments by the Syrian regime."
Sen. Dianne Feinstein, chairwoman of the Senate Intelligence Committee, said she would "welcome" Lavrov's call for Syria to transfer control of its chemical weapons "to prevent an international strike."
"I believe that Russia can be most effective in encouraging the Syrian president to stop any use of chemical weapons and place all his chemical munitions, as well as storage facilities, under United Nations control until they can be destroyed," the California Democrat said.
Former U.S. Secretary of State Hillary Clinton said getting Syria to surrender the stockpiles "would be an important step."
"But this cannot be another excuse for delay or obstruction," Clinton said during an event at the White House Monday. "And Russia has to support the international community's efforts sincerely or be held to account."