Turkey’s president on Monday met his Russian counterpart in the capital Ankara ahead of a trilateral summit on Syria.

Recep Tayyip Erdogan received Vladimir Putin at the Cankaya Palace for a closed-door meeting that lasted around one-and-a-half hours.

Later in the day, the presidents -- to be joined by Iranian President Hassan Rouhani --will gather for the fifth summit on Syria in the Astana format where they will discuss the latest developments in the northwestern Idlib city, the voluntary return of refugees and political solution to the Syrian turmoil.

The Astana peace process -- seeking to end the Syrian conflict -- was launched in January 2017 upon the initiatives of Turkey, Russia, and Iran. A total of 13 rounds have been conducted in Astana, Kazakhstan so far.

Turkey and Russia agreed last September to turn Idlib into a de-escalation zone where acts of aggression are expressly prohibited.

The Syrian regime and its allies, however, have consistently broken the terms of the cease-fire, launching frequent attacks inside the de-escalation zone.