Washington remains “steadfast” in its support for Iraq’s Prime Minister Mustafa Al-Kadhimi and the Kurdistan Regional Government “in their efforts to root out terrorism,” the State Department said late Thursday, November 5.

The outlawed Kurdistan Workers’ Party, or PKK, killed at least one Peshmerga and wounded a few others in Dohuk province on Wednesday, Ahval reported.

The U.S. and Turkey have been allies for more than six decades, but in recent years their relationship has been strained by various disputes. Washington’s latest stance against the PKK in Syria may serve to ease one key tension between them. PKK is estimated to have thousands of affiliated militants within Syria.

Fighters of PKK helped drive Islamic State from the Syrian town of Kobani in 2014 as well as the northern Iraqi town of Shingal in 2015, establishing themselves as a dominant power within the U.S.-backed Syrian Democratic Forces, or SDF. James Jeffrey, the U.S. special representative for Syria, said in an interview that the PKK divides opposition against Syrian President Bashar Al-Assad and poisons relations with Turkey.

“We want to see the PKK cadre leave Syria. That is a major reason why there is tension with Turkey in the northeast,” Jeffrey said in an interview with Syria Direct in Amman on Oct. 30. “Turkey has real concerns about the makeup of the SDF and the presence of the PKK. So the solution is to work to reduce and eventually eliminate that presence.”

Washington and Ankara remain at loggerheads over Turkey’s purchase of a Russian missile-defense system, which the U.S. contends could help Moscow gather intelligence on NATO military projects. Other issues include Washington’s refusal to extradite Fethullah Gulen, the Turkish cleric living in exile in Pennsylvania whom Turkey accuses of orchestrating a coup and the U.S. prosecution of Turkish state-run lender Halkbank.

Last year, Turkey reached separate agreements with the U.S. and Russia to keep Kurdish fighters in Syria away from its border.

In northern Iraq, the PKK vowed to “defend itself” if Peshmerga forces target its bases there, ANF news agency reported Wednesday. The flare-up of tensions prompted Turkey’s main pro-Kurdish political party, HDP to call on the Iraqi Kurdish region’s former president Massoud Barzani, a powerful political figure, to step in.

“You have to secure the Kurdish alliance,” Leyla Guven, the HDP co-chair, said on Thursday, Birgun newspaper reported on Friday. “There is no other way.”

Turkey’s military has carried out numerous incursions and airstrikes against the PKK, which has used northern Iraq as a springboard in its decades-long war for autonomy in Turkey’s southeast. It also maintains military bases originally set up for a peacekeeping mission in the 1990s, designed to enforce a cease-fire between rival Kurdish parties in the area mediated by U.S. and U.K. diplomats. Turkey says its continued presence is a deterrent against the PKK, which has its main base located on Mount Qandil on the Iran-Iraq border.

Reporter’s code: 50101