Ankara summoned on Tuesday the U.S. Ambassador John Bass to the Turkish Foreign Ministry over the State Department spokesman's remarks on 'not considering the PYD, YPG as terrorists'.Turkish-U.S. relations have gone south following the statement from U.S. State Department spokesman John Kirby that the U.S. does not consider the Syrian PKK affiliate Democratic Union Party's (PYD) armed People's Protection Units (YPG) to be a terrorist organization. Kirby's statement was in response to President Recep Tayyip Erdoğan's ultimatum to Washington to choose either Turkey or the PYD as its ally.Even though Ankara repeatedly warned the U.S. and Europe that there cannot be any good or bad terrorists, pointing to the YPG, the U.S. disregarded Erdoğan's last call and designated the YPG as its "partner.""Syrian Kurds are our partners against DAESH," Kirby said, stoking the flames of a rift between Ankara and Washington.Erdoğan's ultimatum to Washington came days after U.S. President Barack Obama's special presidential envoy for the Global Coalition to Counter DAESH, Brett McGurk, paid a visit to PYD-controlled Kobani and held talks. Photos of McGurk's visit to Kobani surfaced on social media. He was seen meeting with former PKK fighters in Syria over the weekend. Polat Can, known as the spokesman and one of the founders of the YPG, shared a photo on his Twitter account showing him presenting a plaque to McGurk.While the U.S., considered a significant ally to Turkey, refers to the YPG as "a strong partner," the PKK-affiliated group released a video in late January in which Westerners were called on to join the group and attack Turkey.Erdoğan, on his way back to Turkey from Latin America over the weekend, asserted that Ankara will exert every effort to make sure that the YPG is designated a terrorist organization in the international arena.Some reports say the YPG has committed human rights violations in places where the group has established cantons. A U.N. report presented by Paulo Sergio Pinheiro to the U.N. Human Rights Council in Geneva in September 2015 said: "Following the YPG's retaking of the previously ISIS [DAESH]- controlled areas of Tal Abyad in early July and villages in the Tel Tamer region of al-Hasakah, YPG fighters reportedly looted houses belonging to Arab villagers."Amnesty International also accused the PYD of violating human rights. According to an Amnesty International report, the PYD autonomous administration in northern Syria is applying pressure by unlawfully detaining and unfairly trying peaceful critics and civilians on the pretext of fighting DAESH.

The PYD administration reportedly detained civilians for periods of up to a year without charge or trial and denied basic rights, including the right to defend themselves, see evidence used against them or access a lawyer.

The PYD is largely accepted as the Syrian wing of the PKK, which is recognized as a terror organization by the U.S., the E.U and NATO.