The United States has officially held the outlawed Kurdistan Workers' Party (PKK) responsible for the killing of 13 kidnapped Turkish citizens in northern Iraq.
US State Department spokesman, Ned Price, said Secretary of State Antony Blinken had spoken to his Turkish counterpart, Mevlut Cavusoglu, and offered his condolences following the death of 13 Turkish citizens in the Gara region of northern Iraq.
"The Secretary expressed condolences for the deaths of Turkish hostages in northern Iraq and affirmed our view that PKK terrorists bear responsibility," the US State Department said in a statement.
Earlier on Monday, the Turkish Foreign Ministry summoned US Ambassador David Satterfield to convey "in the strongest terms" its reaction to a statement on the killing of 13 Turks captured by Kurdish militants, which President Tayyip Erdogan called "a joke".
In its initial response, Washington said it stands with its NATO ally Turkey and condemns in the strongest terms the killing if it was confirmed that the PKK is responsible for it.
Turkish forces found the bodies of the 13 hostages last Tuesday after raiding one of the PKK caves in the Gara region in northern Iraq, as part of 'Operation Eagle Claw-2', which began on 10 February.
The PKK is classed as a terrorist group by Turkey, the United States, and the European Union. The group is responsible for the deaths of more than 40,000 people during its operations that have continued for more than 30 years.