There was no confirmation by Russia of the announcement by President Recep Tayyip Erdogan's spokesman Ibrahim Kalin, who added that Turkey was not planning to attend the event.
Russia was planning to hold the "Congress of Syrian National Dialogue" on November 18 in the Black Sea resort of Sochi to bring together various players in the over six-year conflict.
Several Western states had expressed scepticism over the planned conference, saying peace efforts were better off going through the United Nations.
The plan had been announced by Russia after the latest peace talks on Syria, also backed by Turkey and Iran, in the Kazakh capital Astana.
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"We immediately objected," Kalin told NTV television.
"The Kremlin then got in touch with us and said they were postponing the meeting.
"So as of now, if there is no change, the meeting will not be taking place on November 18 but at a later date.
Despite being on opposite sides of the conflict, Russia and Turkey have been working together intensely since a 2016 reconciliation deal ended a crisis caused by the shooting down of a Russian war plane over Syria.
Russia, along with Iran, is the key backer of President Bashar al-Assad and Moscow's military intervention inside Syria is widely seen as tipping the balance in the conflict. Turkey, however, has backed the rebels seeking Assad's ouster.
Russia and Turkey are now enforcing four so-called de- escalation zones in flashpoint areas in Syria in a bid to pave the way for peace, including the northern Idlib province which is largely controlled by jihadists.