The question may be al-Qaeda's influence on the Syrian rebels, an issue Kerry has downplayed.

Speaking to his human rights council Wednesday, Putin said, "This was very unpleasant and surprising for me. We talk to them (the Americans), and we assume they are decent people, but he is lying and he knows that he is lying. This is sad."

Putin has criticized Obama administration claims that Bashar Assad's government attacked the rebels with chemical weapons.

Last month, Obama canceled a summit meeting with Putin after a series of U.S.-Russian disputes, including Russia's decision to grant asylum to National Security Agency leaker Edward Snowden.