Russia says it has given the United States its plan for securing Syria's chemical weapons ahead of at least two days of talks beginning Thursday in Geneva between U.S. Secretary of State John Kerry and his Russian counterpart.
Sergei Lavrov gave no details of the proposal but said he would discuss it with Kerry during their meetings. Kerry has said reaching any agreement on a chemical weapons plan would be "exceedingly difficult."
A team of U.S. arms experts will accompany the top U.S. diplomat, who will also meet with U.N.-Arab League special envoy on Syria, Lakhdar Brahimi, while in Geneva.
State Department spokeswoman Jen Psaki said the U.S. will not "play games" at the talks, will only accept a credible proposal and retains the option of military strikes if negotiations fail.
"At the same time, our military remains in the same position, it's maintaining its current posture to keep pressure on the [Syrian] regime, and we have that in our back pocket as well."
Meanwhile, envoys from the five permanent veto-wielding members of the U.N. Security Council -- Britain, China, France, Russia and the United States -- prepared to discuss a proposed U.N. resolution that aims to ensure the Russian plan is implemented quickly.
Moscow already has rejected key elements of what the U.S. and France say must be a binding U.N. resolution, including tough language allowing military force against Syria to ensure compliance.
U.N. Secretary General Ban Ki-moon said earlier Wednesday that the failure to halt atrocities in Syria had become a new stain on the reputation of the world body and the Security Council powers.
In a speech Tuesday, U.S. President Barack Obama referred to the Russian proposal and Syria's reported agreement as "encouraging signs," but also stressed that the U.S. military would be ready to respond if diplomacy fails.
Under the deal, Syrian President Bashar al-Assad's government would surrender its chemical weapons to the United Nations to have them destroyed, and the United States would put off its plans for a military strike.
Mr. Obama asked Congress to postpone a vote authorizing military action against Syria to let the diplomatic initiatives play out.
Iran and China, which have opposed outside military intervention in Syria, expressed optimism about the diplomatic path on Wednesday.