The United States on Sunday condemned the execution of 13 Turkish hostages held by PKK terrorists in northern Iraq.

"We stand with our NATO Ally Turkey and extend our condolences to the families of those lost in the recent fighting. The United States deplores the death of Turkish citizens in the Kurdistan Region of Iraq," U.S. State Department spokesperson Ned Price said in a statement.

Price said that if reports that the PKK was responsible were confirmed, they "condemn this action in the strongest possible terms."

The executions, which included military and police personnel, took place during a Turkish military operation launched on Feb. 10 against the PKK, in which 48 militants were also killed, according to Turkish Defense Minister Hulusi Akar.

Earlier on Sunday, Akar revealed that the PKK terrorists executed 13 Turkish citizens in a cave in northern Iraq after abducting them. Most were shot in the head.

Turkey has long been stressing that it will not tolerate threats posed to its national security and has called on Iraqi officials to take the necessary steps to eliminate the terrorists. Ankara previously noted that if the expected steps were not taken, it would not shy away from targeting the group. Recently, Akar expressed that Turkey was prepared to provide assistance to Iraq in clearing terrorists from the region. Iraq's Kurdistan Regional Government (KRG) has called the PKK's presence in Sinjar unacceptable and urged the militants to leave the area.

Turkey launched Operations Claw-Tiger and Claw-Eagle last June to ensure the safety of Turks and its national borders by eliminating terrorist threats. Operation Claw-Eagle 2 was launched last week.

In its more than 40-year terrorist 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 and children.