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.
Russia has developed an unmanned submarine capable of carrying a powerful nuclear munition. Two years ago, the Americans could not even think Russia could do it
The head of the Russian Finance Ministry, Anton Siluanov, said that the Americans would suffer additional losses if they impose sanctions on Russia's public debt