The U.S. Defense Department said Saturday that the U.S.-led coalition was not involved in any operation in northwestern Syria's Afrin, adding its focus was still on the fight against the Daesh terror group.

"We understand Turkey's security concerns regarding the PKK, which is recognized as a foreign terrorist organization by the U.S.," Pentagon spokesman Major Adrian Rankine-Galloway said, calling on all parties to stop increasing the tension in the region.

The Turkish Armed Forces launched Operation Olive Branch, which complies with international law and U.N. Security Council resolutions, against terrorist groups such as the PKK and its affiliates KCK, PYD, YPG, and Daesh in Afrin region to improve Turkey's national security and prevent a "terror corridor" from being formed along its southern border.

A total of 108 out of 113 previously identified terrorist targets in seven regions were hit during the operation by 72 Turkish warplanes, while ground troops located in southern Turkey's southeastern Kilis province near the Syrian border supported Operation Olive Branch with howitzers, tank units and multiple rocket launchers.

Turkish Chief of General Staff Gen. Hulusi Akar held a phone call with U.S. Chairman of the Joint Chiefs of Staff Gen. Joseph Dunford prior to the counter-terror operation, the military announced Saturday.

After the launch of Operation Olive Branch, the mission chief employed by the U.S. embassy was also invited to the Foreign Ministry in Ankara to be given a briefing on the latest developments in Afrin.

The operation in Afrin – bordering Turkey's Hatay and Kilis provinces – was widely expected in the wake of Turkey's Operation Euphrates Shield in northern Syria, which cleared Daesh terrorists from Turkey's border between Aug. 24, 2016 and March 2017.