Turkish President Recep Tayyip Erdoğan held a telephone conversation with his Russian counterpart Vladimir Putin on Friday.
Erdoğan and Putin exchanged views on a wide range of issues, particularly the escalating tensions in Syria's Idlib region.
During the critical conversation, Erdoğan expressed Turkey's concerns over heightened tensions in the rebel-controlled region.
Turkish leader told his Russian counterpart that the Assad regime's attacks in northwest Syria are causing a humanitarian crisis, and posing a threat to Turkey's national security.
Erdoğan reportedly reiterated that the attacks violated a ceasefire in Idlib and damaged efforts for a political solution in Syria.