Diplomatic sources said Kalın conveyed to Bolton that the Turkish side had completed preparations for the realization of the Turkish-US joint operation plan without delay.
The call comes a day after President Recep Tayyip Erdogan slammed international powers over their inaction on the establishment of a safe zone in northern Syria.
He said the safe zone was nothing more than a name as no other country except Turkey was willing to take action. He also warned that the de-escalation zone in the Idlib region was slowly disappearing because of military attacks by Assad regime forces.
On Aug. 7, Turkish and US military officials agreed to set up a safe zone and develop a peace corridor running from the Euphrates River to the Iraqi border to facilitate the return of displaced Syrians currently living in Turkey to their home country and provide security for Turkish border settlements and military outposts. They also agreed to establish a joint operations center.