A senior U.S. Marine Corps official told lawmakers he believes that Russia’s drone incursion into Polish airspace earlier this week was most likely intentional.

Gen. Christopher Mahoney, the current Assistant Commandant of the Marine Corps and President Donald Trump’s nominee to be the next vice chairman of the Joint Chiefs of Staff, told the Senate Armed Services Committee on Thursday that his “assessment, based on what I know, is that it looks more intentional than not.”