Russian Foreign Minister Sergei Lavrov has held his first direct talks with Syria's opposition leader on the sidelines of the Munich Security Conference.
The meeting Saturday between Lavrov and Moaz al-Khatib did not include U.S. Vice President Joe Biden and U.N. envoy Lakhdar Brahimi, despite initial suggestions that all four might meet in southern Germany. Biden instead held separate meetings with Lavrov, Brahimi, and al-Khatib.
This year's Munich Security Conference is designed to revive efforts to find a means to end the civil war in Syria. Earlier this week, al-Khatib said he is willing to negotiate with Syrian President Bashar al-Assad's government.
The White House says the vice president emphasized during his meeting with Lavrov the importance of Russia and the U.S. working together in the interest of international peace and security.
Washington and Moscow have considerable disagreements on dealing with the Syrian crisis.
Biden pledged continuing U.S. support for Syria's opposition at the conference, adding that President Bashar al-Assad is "no longer fit" to lead his country and "must go."
Russian Foreign Minister Sergei Lavrov said at the conference that such a condition is not acceptable.
He said the agreed-upon Geneva process for Syria must be followed, including talks among all parties. He also rejected a suggestion from an audience member for the creation of a humanitarian corridor in Syria, enforced by international air power.
"On the humanitarian corridors with close air support, no," he said. "Any use of force, any threat of the use of force will be unacceptable because the situation on the ground requires not more military assets but immediate cease-fire and immediate end of violence."
Lavrov indicated Russia is concerned that any United Nations authorization for military operations in Syria, even for humanitarian purposes, will result in wider involvement, which is what Russia believes happened with the U.N. Security Council resolution on Libya. The Damascus ally has vetoed three U.N. resolutions to mount pressure on Syrian President Bashar al-Assad.
Civil war between Syrian rebels and the government of President Assad has gripped Syria since evolving from peaceful anti-government protests in March of 2011.
The United Nations says at least 60,000 people have been killed since the conflict began.