Paris (AFP) - US Secretary of State John Kerry said Wednesday he would head to Moscow next week to meet Russian leaders and try to build momentum for a push to end Syria's civil war.
Washington and Moscow have worked together to bring a group of regional and world powers together to forge a framework for a Syrian ceasefire and political transition.
But signs of tension have begun to rise again as the United States seeks to host the next meeting of the "International Syrian Support Group" in New York on December 18.
Russia has said it is too soon to confirm the New York talks will go ahead while Saudi Arabia is still meeting Syria's divided opposition factions.
The Saudi effort is designed to assemble a delegation of rebel and opposition leaders to negotiate with the government of Syrian President Bashar al-Assad.
But Moscow, a long-standing ally of Assad's regime, considers some of the armed groups opposing him to be "terrorists" and may oppose their inclusion.
Asked about President Vladimir Putin's role, Kerry said: "I'm, I think, travelling to Moscow in a week and we'll be meeting with him and with Foreign Minister (Sergei) Lavrov on the subject of Syria and of Ukraine.
"They have helped us in response to this," he said at an event organised by the International New York Times on the sidelines of the UN climate summit in Paris.
"Russia has been constructive in helping the Vienna process to take place, to be successful and I think they want a political settlement there, I believe that.
"Now, do they have interests there that are different from ours? Yes, they do. Are they protecting those interests? Of course they are," he said.
Kerry said Russia had made no secret of its political and military support for Assad, but that he felt there was enough common ground to move forward on the peace process.