U.S. Defence Secretary Pete Hegseth has accepted a luxury Boeing 747 aircraft from Qatar for U.S. President Donald Trump to use as Air Force One, the Pentagon said Wednesday, despite ongoing questions about the ethics and legality of taking the expensive gift from a foreign nation.

The U.S. defence department will "work to ensure proper security measures" on the aircraft to make it safe for use by the president, Pentagon spokesman Sean Parnell said. He added that the plane was accepted "in accordance with all federal rules and regulations."

Trump has defended the gift, which came up during his recent Middle East trip, as a way to save tax dollars.

"Why should our military, and therefore our taxpayers, be forced to pay hundreds of millions of Dollars when they can get it for FREE," Trump posted on his social media site during the trip.

Democrats, some Republicans have concerns

Others, however, have said Trump's acceptance of an aircraft that has been called a "palace in the sky" is a violation of the Constitution's prohibition on foreign gifts. Democrats have been united in outrage, and even some of the Republican president's GOP allies in Congress have expressed concerns.