Trump confirms he secretly switched planes after a reported threat to his life, leaving journalists aboard Air Force One.

Donald Trump confirmed Tuesday that he secretly switched planes because of a threat to his life, after the Washington Post revealed the US president was smuggled out of Air Force One to a different aircraft on a catering truck.

"They wanted me to go in a different flight, a different plane – equal safety, but they wanted me to do it, so I do it. I do what they say," Trump told reporters during a gaggle.

"I guess there was a threat out there. I didn't really ask too much about it."

The newspaper reported Monday that the secret operation reportedly smuggled Trump off Air Force One before the plane departed, still carrying journalists and top aides who remained at apparent risk of an Iranian strike.