Turkey has asked Russia’s permission to begin an air-campaign in Syria’s Afrin region.
In response Syria says it is prepared to shoot down any planes which enter its airspace.
Amid rising tensions Turkey has send reinforcements to its border with Afrin.
The region is controlled by Syrian-Kurds who have strong support from the US military.
But Turkey is Washington's main Muslim ally within NATO.
Speaking to CNN Turk Turkish Foreign Minister Mevlut Cavusoglu said:
"We will intervene in Afrin. We will also take steps in the east of the Euphrates, as well as Manbij, against threats towards us. We would not want an ally like the U.S. against us in this situation."
"We are meeting with Russians and Iranians on the usage of airspace (in the Afrin operation)"
Military re-enforcements are heading to the boarder