Syria said it will acknowledge that it possesses chemical weapons and is willing to sign onto the convention banning them, according to a new report from the Associated Press.
"We fully support Russia's initiative concerning chemical weapons in Syria, and we are ready to cooperate. As a part of the plan, we intend to join the Chemical Weapons Convention," Syrian Foreign Minister Walid Muallem was reported to have said in an interview.
The concessions come just hours ahead of a speech by President Barack Obama in which he originally was expected to urge Congress to approve a military strike on Syria for its alleged use of chemical weapons against rebel forces there. It then was expected that he would admonish and urge Syrian President Bashar al-Assad to turn over its chemical weapons to international authorities.
The White House response to the latest developments is not yet known, though Obama previously said of potential new pledges, "To paraphrase Ronald Reagan ... we don't just trust, but we also verify."
"I'm sure they're scrambling right now with edits [of Obama's speech], because the situation on the ground is changing as we speak," Marc Thiessen, a former speechwriter for President George W. Bush, told CNBC's "Squawk on the Street." "It's a very different speech than it was 24 hours ago."
Former Pennsylvania Gov. Ed Rendell, a Democrat, said that the turn of events is fortuitous for the White House. "The president got lucky. ... It was going to be very tough to get enough Democrats and Republicans in the House to approve military action."
Rendell added that any agreement with Assad should come with the understanding that if the Syrian regime violates it, the U.S. will respond quickly with force, hopefully with benefit of backing from the international community.
Earlier, a White House official said Obama agreed to discussions at the United Nations Security Council on a proposal from Russia to secure Syria's chemical weapons stockpiles.
The official said Obama discussed the proposal Tuesday with French President François Hollande and British Prime Minister David Cameron. France's foreign minister says France will float a resolution in the U.N. Security Council aimed at forcing Syria to make public its chemical weapons program, place it under international control and dismantle it.
Obama said the proposal marked a potential breakthrough that could halt plans for a U.S. military strike, though he said the details remain unclear.
The official requested anonymity because the officials was not authorized to discuss the private conversations.
Syria, meanwhile, said it accepted Russia's proposal to place its chemical weapons under international control for subsequent dismantling.
Syrian Foreign Minister Walid al-Moallem said Tuesday after meeting with the Russian Parliament speaker that his government quickly agreed to the initiative to "derail the U.S. aggression."
Richard Murphy, former U.S. Ambassador to Syria, told CNBC that "when you look at the Syrian government and their decision-making, the speed with which this proposal was made and accepted was a little curious."
Russia Foreign Minister Sergey Lavrov said that his country is now working with Syria to prepare a detailed plan of action, which will be presented shortly.
Lavrov said that Russia will then be ready to finalize the plan together with U.N. Secretary General Ban Ki-moon and the Organization for the Prohibition of Chemical Weapons.
Secretary of State John Kerry told a House panel Tuesday that the Obama administration will give any proposal a hard look but that it must not be used as a delaying tactic and that it has to be verifiable, real and include tangible conditions for Assad to forfeit his chemical weapons.
Defense Secretary Chuck Hagel said that in order for Syria to feel enough pressure to turn its chemical weapons over to international controls, the U.S. must present a credible threat of military action.
Hagel told a congressional committee Tuesday that lawmakers must endorse military action to give the diplomatic effort more urgency and energy. Hagel and Kerry continued the administration's campaign to get congressional approval of a limited military action in Syria.
But the delay in using force may be raising questions about U.S. credibility.
"There's a great deal of credibility [the U.S.] has already lost with saying there is going to be a strike and then there wouldn't be a strike," Medal of Honor recipient Colonel Jack Jacobs told "Squawk on the Street" on Tuesday. "Our credibility is wafer thin around the world, and particularly in that region."
"The waffling of the president makes it extremely difficult for the United States—and particularly the secretary of state—to operate in the halls of power of other countries. … It's going to be very hard for the secretary of state to convince other leaders that in fact we mean what we say," he said.
— The Associated Press with CNBC