A reporter tweeted he saw an object that looked like a drone and said the modified Boeing 757 flew "right over a small object, remarkably close to the president's plane" as Trump returned to Washington from New Jersey.
The 89th Airlift Wing said on Monday it "is aware of the report. The matter is under review."
The Air Force noted the plane landed safely without incident just before 6 p.m. on Sunday.Any plane the president is flying on is designated as Air Force One.