The helicopter is reported to have crashed in the Turkish Hatay Province on the border with Syria’s Afrin region where Ankara is conducting a military campaign against Kurdish forces.

READ MORE: Turkey v NATO: Will Ankara’s Syria incursion destroy ties with partners?

“They will pay the price for this,” Erdogan said, without specifying who exactly was responsible for the downing of the aircraft.

The Turkish Operation Olive Branch in the Afrin region in northern Syria entered its fourth week on Saturday. The campaign followed Ankara’s promises to “strangle” the new Border Security Force (BSF) in Syria.

Earlier in January, the US-led coalition announced that it would help create the 30,000-strong BSF, half of which would be made up of the Kurdish Syrian Democratic Forces (SDF) alliance.

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