The leaders of the three countries - who have positioned themselves as the key foreign players in Syria's long-running war - were meeting for talks on how to work more closely together in resolving the conflict.
Putin said the talks were "constructive and business-like" and that "close coordination" was crucial to ensuring long-term stability in Syria.
He said the three agreed to "strengthen cooperation" in the so-called Astana framework - a process initiated by Russia, Iran and Turkey that has eclipsed parallel peace talks led by the United Nations. They also agreed to work together to put together a constitutional committee that would work to resolve Syria's political future, Putin said, adding that another round of talks would take place in Astana in late March and early April. Rouhani said Thursday's talks were "very helpful and frank" and insisted on Syria's territorial integrity, calling for a "purge of terrorists" from the rebel-held northwestern province of Idlib. He also suggested he didn't believe the US was planning to withdraw from Syria. "We have no optimism about what the Americans say... but if they do withdraw, it will be very good news."