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 the conflict in Syria.

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 the conflict in Syria.

Washington and Moscow have jointly worked to reach 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 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.

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 (Sergey) Lavrov on the subject of Syria and of Ukraine.

"They have helped us in response to this," he said at an event organized 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 Syrian President Bashar al-Assad, but that he felt there was enough common ground to move forward on the peace process.