The fight against YPG/PKK terror group has been alluded to in the joint statement released following the visit of the U.S. Secretary of State Rex Tillerson to Turkey.
The YPG is the PKK terrorist organization's Syrian offshoot.
Foreign Minister Mevlüt Çavuşoğlu met his U.S. counterpart in Ankara following which a joint statement was released that said: "Turkey and the United States reiterate their resolve to fight against Daesh, PKK, Al-Qaeda and all other terrorist organizations and their extensions."
The reference to terror groups and "their extensions" points to a new understanding in the diplomatic discourse of the U.S.
The joint statement highlights that Ankara and Washington have reached a mutual understanding on the issue.
The U.S. has called the PYD/PKK a "reliable ally" in its fight against Daesh, despite strong protests by Turkey, which has highlighted the PYD/PKK's continuing terrorist threat to both Syrians and Turkey's border regions.
When asked by a foreign journalist whether Turkey would back down from its decision to purchase S-400 missile system from Russia if a sanctions threat came from the U.S., Çavuşoğlu rejected the use of the word "threat" and said: "We never use the language of threat and we also reject it as it is not a good thing.
"However, as Rex also said, we haven't talked about this issue just yesterday evening and today."
On Jan. 20, Turkey launched Operation Olive Branch to clear PYD/PKK and Daesh terrorists from Afrin, northwestern Syria.
According to the Turkish General Staff, the operation aims to establish security and stability along Turkey's borders and the region as well as to protect Syrians from terrorist oppression and cruelty.
The operation is being carried out under the framework of Turkey's rights based on international law, UN Security Council resolutions, its self-defense rights under the UN charter, and respect for Syria's territorial integrity, it said.
