President Donald Trump on Wednesday night departed Turkey aboard an old Air Force One before switching to the newly Qatari-gifted and refurbished Air Force One, seen here, in Britain. File Photo courtesy U.S. Air Force/UPI | License Photo

July 9 (UPI) -- President Donald Trump unexpectedly departed Turkey aboard an older Air Force One and then switched in Britain to the newly renovated Qatari-gifted jet he had arrived in Ankara on before heading home.

The reason for the change was not immediately clear. The president said the new aircraft had been sent ahead so U.S. troops in Britain could see it, but the switch also prompted questions about security after he repeatedly said earlier Wednesday that he was "number one" on Iran's kill list.

Trump departed Ankara, where he was for the two-day NATO summit, aboard an older Air Force One at 8:45 p.m. local time Wednesday, landing at Royal Air Force Base Mildenhall in Suffolk, Britain, at 10:16 p.m. local time, where he deplaned and then boarded the new Air Force One.

The Qatari-gifted plane was wheels up at 11:14 p.m., en route to the United States.