ANKARA (Reuters) - Syrian Kurdish fighters must return to the east of the Euphrates river or Turkey will “do what is necessary”, Foreign Minister Mevlut Cavusoglu said on Wednesday, after Turkish forces launched an operation in northern Syria.

Turkish special forces, tanks and jets backed by warplanes from the U.S.-led coalition launched an operation into northern Syria on Wednesday to try to wipe Islamic State militants from the border and prevent further gains by Kurdish fighters.

Cavusoglu, who was speaking in Ankara, also said that no one would be brought in from the outside and settled in the Syrian town of Jarablus, the border town held by Islamic State that Turkey is targeting in the operation.