Putin made his surprise announcement, that came with no advance word to the United States, at a meeting with his defense and foreign ministers.
Russian forces had largely fulfilled their objectives in Syria, Putin said. But he gave no deadline for the completion of the withdrawal and said forces would remain at a seaport and airbase in Syria's Latakia province.
In Geneva, United Nations mediator Staffan de Mistura told the warring parties there was no "Plan B" other than a resumption of conflict if the first of three rounds of talks that aim to agree a "clear roadmap" for Syria failed to make progress.
Putin and US President Barack Obama spoke by phone on March 14 about Syria, with the Kremlin saying the two leaders "called for an intensification of the process for a political settlement" to the conflict.
The White House said Obama welcomed the reduction in violence since the beginning of the cessation of hostilities but "underscored that a political transition is required to end the violence in Syria.”