Speaking in Ankara, Graham also said he believed U.S. Chief of Staff Joseph Dunford was working on a plan with Turkey to move Kurdish YPG elements away from the Turkish border.

Trump announced last month that Islamic State had been defeated in Syria and he would pull U.S. forces out of the country. A bomb attack this week claimed by the militant group killed two U.S. troops and two civilians working for the U.S. military in northern Syria, along with other civilians.

The attack in Manbij appeared to be the deadliest on U.S. forces in Syria since they deployed on the ground there in 2015. The town is controlled by a militia allied to U.S.-backed Kurdish forces.

It remains unclear when U.S. forces will leave northern Syria, where both Turkey and the Syrian government of Bashar al-Assad are ready to fill the vacuum. The YPG militia allied to the fighters holding Manbij last month invited Assad into the area around the town to forestall a potential Turkish assault, Reuters reported.

Erdogan said last week he had discussed a safe zone with Trump, which Turkey would set up inside Syria along their border.

“Here’s the good news: General Dunford, I think, has a plan that he’s working on with the Turkish military that can accomplish these objectives and they are to move the YPG elements away from Turkey,” said Graham, adding heavy armaments should be taken from the Kurdish groups.

Graham also said the political arm of the YPG was interlinked and interconnected with the PKK.

“A withdrawal that does not outline the points I have made will not end the war against IS (Islamic State), it will start a new war,” he said.

“This war will be a necessity by Turkey, to go into Syria and clear out armed elements that Turkey believes poses a threat to its sovereignty.”

Reporter’s code: 50101