U.S. State Department Spokesperson Heather Nauert said Thursday "some of the forces [YPG/PKK] that we're working with in the east, we are seeing [that they're] starting to go to Afrin."
Speaking at a press conference, Nauert said those forces that the U.S. was working with "have familial relations, familial ties there, perhaps that's part of the reason why."
Reiterating a previous statement, Nauert said "what is going on in Afrin is taking away from the fight against ISIS [Daesh]," adding the U.S. was in Syria to fight the Daesh terror organization.
The U.S. has called the PKK terror group's Syrian affiliate the People's Protection Units (YPG) a "reliable ally" in its fight against Daesh, despite strong protests by Turkey, which has highlighted the YPG/PKK's continuing terrorist threat to both Syrians and Turkey's border regions.
Turkey has also repeatedly urged the U.S. to stop its military support for the YPG, but to no avail. So far, the U.S. has provided 2,000 planeloads and 5,000 truckloads of weapons and ammunition to the YPG terrorists.
Operation Olive Branch was launched by Turkey on Jan. 20 to remove the PKK and its affiliate the Democratic Union Party (PYD) and its armed wing the YPG, as well as Daesh terrorists from Afrin in northwestern Syria.
According to the Turkish General Staff, the operation aims to establish security and stability along Turkish borders and in the region as well as to protect Syrian people from the oppression and cruelty of terrorists.
The operation is being carried out under the framework of Turkey's rights within international law, U.N. Security Council resolutions, its right to self-defense under the U.N. charter and respect for Syria's territorial integrity, it said.
The operation in Afrin – bordering Turkey's Hatay and Kilis provinces – was widely expected in the wake of Operation Euphrates Shield in northern Syria, which cleared Daesh terrorists from Turkey's border between Aug. 24, 2016 and March 2017.
Afrin has been a major hideout for the PKK/PYD/YPG since July 2012 when the Assad regime in Syria left the city to the terrorist group without putting up a fight.