In talks that stretched late into Tuesday night in Moscow, US Secretary of State John Kerry met first for more than two hours with President Vladimir Putin and then for a further three with Foreign Minister Sergei Lavrov.
"We agreed that Russia and the United States will encourage both the Syria government and opposition groups to find a political solution," Lavrov told reporters at a concluding news conference that ended after midnight.
Lavrov and Kerry said they hoped they could convene an international conference by the end of May to build on the Geneva accord agreed by world powers last June for a peaceful solution in Syria.
The Geneva agreement, which was never implemented, set out a path toward a transitional government without ever spelling out the fate of President Bashar al-Assad.
The six-point accord -- negotiated by the last UN-Arab League envoy to Syria Kofi Annan -- "should be the road map... by which the people of Syria can find their way to the new Syria and in which the bloodshed, the killing, the massacres can end", Kerry said.
And in what appeared to be a major concession to Russian concerns of instability in its Middle East ally, Kerry seemed to soften the US stand on Assad's future.
Washington has long insisted Assad must go.
But Kerry told reporters that only the Syrian government and the opposition can determine the make-up of a transitional government to shepherd the war-torn nation towards democratic elections.
"It's impossible for me as an individual to understand how Syria could possibly be governed in the future by the man who has committed the things that we know have taken place," Kerry said as he wrapped up his first visit in office to Russia.
Lavrov said both Russia and the United States were ready to use all their resources to bring "the government and opposition to the negotiating table."
Russia has long accused the West of worsening the Syria conflict by seeking to topple the Assad government.
The unrest in Syria began in March 2011, and many people, including large numbers of army and security personnel, have been killed in the violence.