Turkish Defence Minister Hulusi Akar and his US counterpart Mark Esper spoke over the phone on Wednesday and agreed to flesh out the first phase of implementing the zone, Anadolu news agency reported, adding that delegations from both sides are expected to meet in Ankara "soon".

The first phase is expected to be launched later this week and will see joint patrols of Turkish and US soldiers.

But negotiations on the scope and implementation are still ongoing, with the main sticking point being the size of the zone.

In a joint statement released on August 7, the NATO allies said the safe zone would become a "peace corridor", without providing further details. At the time, the Syrian government called the agreement a "blatant attack" on the country's sovereignty.

A joint operations centre is to be created in Sanliurfa in Turkey's southeast, 130 kilometres from the border with Syria and about 330km from Syria's Idlib, where bombardment of rebel groups is ongoing.

Reporter’s code: 50101