Ankara, Moscow and Tehran have agreed to hold the Syrian National Dialogue Congress, Turkey's President Recep Tayyip Erdogan said on Wednesday.
"We hope that this fruitful cooperation between our countries will have a positive effect on the whole region and reduce tensions and the risk of sectarian disintegration in the region," Erdogan said at a news conference with his Russian and Iranian counterpart.
Erdogan, Vladimir Putin and Hassan Rouhani met in Russia's Black Sea city of Sochi to discuss progress made in the Astana peace talks and changes in de-escalation zones across Syria.
The zones were established to reinforce a cease-fire introduced by the three guarantor states last December.
Erdogan said the three countries supported the territorial integrity and sovereignty of Syria.
He added Turkey, Russia and Iran reached a consensus on an "inclusive and fair" political transition process in Syria.
However, Erdogan warned that Turkey cannot share a platform with any terrorist organization that poses a threat to its national security.
"Exclusion of terrorist elements -- that target both Syrian political union and territorial integrity and our country -- from the process, will be among our priorities as Turkey," he added.
Putin said he will host a dinner for Erdogan and Rouhani.