The US President expressed the opinion that Russia's violation of Polish airspace during a drone attack on Ukraine could have been a mistake.

The head of the White House stated this to reporters, Ukrinform reports with reference to The Washington Times.

"It could have been a mistake, but I'm still not happy with what's going on with this situation," he said.

As Ukrinform reported, earlier Trump expressed surprise at the fact that Russian drones violated Polish airspace.

On the night of September 10, about two dozen Russian drones flew into the territory of Poland, several of them were shot down.

Polish Foreign Minister Radoslav Sikorski stated that the nighttime incursion of Russian drones into Polish airspace was not a random event.