U.S. Special Envoy for Syria James Jeffrey said Monday that Washington’s support for armed groups in northern Syria was temporary.

The U.S.’s relationship with the SDF -- a group spearheaded by the YPG/PKK terrorist group – is "tactical" and "transactional", Jeffrey said in a speech at the Atlantic Council, a Washington, D.C.-based think-tank

"We don’t have permanent relations with sub-state entities," he said, adding the U.S. supported the SDF with the specific goal of fighting against Daesh.

The U.S. has been working alongside the YPG/PKK in Syria in an effort to eliminate Daesh from the region.

Ankara views the YPG as the Syrian extension of the PKK, a designated terrorist group in Turkey, the EU and the U.S.

In its more than 30-year terror campaign against Turkey, the PKK has been responsible for the deaths of some 40,000 people, including women and children.