Turkish Defense Minister Hulusi Akar and U.S. Secretary of Defense Mark Esper on Friday discussed latest developments in Syria.

Akar and Esper exchanged views on Turkey's anti-terror operation in northeastern Syria, defense and security.

The ministers agreed to continue with contacts.

The meeting came on the sidelines of the second day of NATO defense ministers meeting in Brussels.

On Oct. 9, Turkey launched Operation Peace Spring to eliminate terrorists from northern Syria east of the Euphrates River in order to secure Turkey’s borders, aid in the safe return of Syrian refugees, and ensure Syria’s territorial integrity.

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. The YPG is the Syrian offshoot of the PKK.