The U.S. military shot down an armed Turkish drone that was operating near its troops in Syria.

Early Thursday morning local time, U.S. forces observed Turkish drones that were conducting airstrikes in the vicinity of Hasakah, some of which landed within a declared U.S. restricted operating zone, Pentagon spokesman Brig. Gen. Patrick Ryder told reporters. The strikes were “approximately a kilometer away” from U.S. forces, he said, while another Turkish UAV reentered the restricted zone and got closer to U.S. troops.

HOUSE SPEAKER RACE ENDORSEMENT LIVE TRACKER: WHO HAS BACKED WHO SO FAR?

U.S. F-16 fighters ultimately shot it down, and no U.S. troops were injured in the incident. U.S. commanders consider the action as one taken in "self-defense," Ryder said, adding that it's not believed that they were intentionally targeting U.S. forces.

Secretary of Defense Lloyd Austin spoke with his Turkish counterpart Yasar Guler to discuss activity relating to U.S. forces in Syria. The leaders spoke about the situation, which Ryder characterized as "regrettable," due to their NATO connection.

"The Secretary reaffirmed that the United States remains in Syria exclusively in support of the campaign to defeat ISIS," Ryder said.

CLICK HERE TO READ MORE FROM THE WASHINGTON EXAMINER

For the last several days, Turkey has retaliated against the Kurdistan Workers' Party for a suicide bombing that took place in Ankara last weekend. Following the bombing, Turkish Foreign Minister Hakan Fidan said the two assailants arrived from Syria, where they had been trained.

The U.S. has roughly 900 troops in Syria still carrying out the department's defeat ISIS mission.