Turkish and Russian military chiefs held a phone talk to discuss developments in Syria, the Turkish army said on Thursday. 

Turkey's Chief of General Staff Yasar Guler and his Russian counterpart Valery Gerasimov exchanged views on Syria where the two countries hold joint patrols under a deal, the Turkish Armed Forces said on Twitter.

No further details were provided over the phone conversation.

As part of a deal, Ankara and Moscow agreed on Oct. 22, both countries have so far carried out a total of 11 joint patrols east of the Euphrates River in northern Syria.

Turkey on Oct. 9 launched Operation Peace Spring to eliminate YPG/PKK terrorists from northern Syria east of the Euphrates River in order to secure Turkey’s borders, aid in the safe return of Syrian refugees and ensure Syria’s territorial integrity.

Under two separate deals with the U.S. and Russia, Turkey paused the operation to allow the withdrawal of YPG/PKK terrorists from the planned northern Syria safe zone.

But the terrorists have failed to withdraw from some areas and continue to attack both soldiers and civilians.

In its more than 30-year terror campaign against Turkey, the PKK -- listed as a terrorist organization by Turkey, the U.S. and the European Union -- has been responsible for the deaths of 40,000 people, including women, children and infants. The YPG is the Syrian offshoot of PKK.