A U.S. official in Ankara opposed the information that the Turkish military had carried out an air assault on northern Iraq on Sunday.
It was reported on Sunday that jets bombed Kurdish rebel targets in Iraq that day.
But the U.S. embassy in Ankara said there was no evidence of attack.
Turkish Foreign Minister didn’t give any comments, but noted that the U.S. officials would be informed about all cross-border operations.
More than 37,000 people have been killed in the conflict since the PKK launched an armed independence campaign in Turkey's southeast in 1984.
The PKK is listed as a terrorist organization internationally by a number of states and organizations, including the USA, NATO and the EU.
"There should be no Russian who goes to sleep without wondering if they're going to get their throat slit in the middle of the night,” Milley said