WASHINGTON 

The U.S. chairman of the Joint Chiefs of Staff and chief of the Turkish General Staff discussed Syria and cooperation between the two nations, a Pentagon spokeswoman said Thursday.

Gen. Mark Milley spoke with Gen. Yasar Guler on Wednesday over the phone, the day Turkey launched its third military operation against the YPG, the Syrian affiliate of the PKK terror group, Col. DeDe Halfhill said in a statement.

"The two leaders discussed the security situation in Syria and the importance of U.S.-Turkish cooperation in the region," she said.

The statement also said both nations "enjoy a strong and continuous military-to-military relationship as key members of the NATO alliance."

Trump announced Sunday the pullback of U.S. forces ahead of Turkey's Operation Peace Spring, a move that has drawn stiff resistance from Capitol Hill.

Turkey launched the operation to secure its borders by eliminating terrorist elements and to ensure the safe return of Syrian refugees and Syria’s territorial integrity.

Ankara wants to eliminate terrorist elements from the PKK and its Syrian offshoot, the PYD-YPG.

In its more than 30-year terror campaign against Turkey, the PKK -- listed as a terrorist organization by Turkey, the U.S. and the European Union -- has been responsible for the deaths of 40,000 people, including women, children and infants.

*Kasim Ileri contributed to this story