Washington. Defense Secretary Pete Hegseth has accepted a luxury Boeing 747 aircraft from Qatar for 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 Defense 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.

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.

They also have noted the need to retrofit the plane to meet security requirements, which would be costly and take time.

"Far from saving money, this unconstitutional action will not only cost our nation its dignity, but it will force taxpayers to waste over 1 billion in taxpayer dollars to overhaul this particular aircraft when we currently have not one, but two fully operational and fully capable Air Force One aircraft," said Senator Tammy Duckworth, a Democrat.

She said during a hearing Tuesday that it is a “dangerous course of action” for the United States to accept the aircraft from the Qatari ruling family.

Air Force Secretary Troy Meink told senators that Hegseth has ordered the service to start planning how to update it to meet needed standards and acknowledged that the plane will require “significant” modifications.

The Air Force, in a statement, said it is preparing to award a contract to modify a Boeing 747 aircraft, but that any details are classified.

Trump was asked about the move Wednesday while he was meeting in the Oval Office with South African President Cyril Ramaphosa. “They are giving the United States Air Force a jet,” Trump said, bristling at being questioned about the gift by a reporter.

Trump said it was given “not to me, to the United States Air Force, so they could help us out” and noted that “Boeing’s a little bit late, unfortunately."

Ramaphosa, who was sitting next to Trump in the Oval Office and has been working to repair his relationship with the president, said, “I’m sorry I don’t have a plane to give you.”

“If your country was offering the United States Air Force a plane, I would take it,” Trump said.

Trump has presented no national security imperative for a swift upgrade rather than waiting for Boeing to finish new Air Force One jets that have been in the works for years.

He has tried to tamp down some of the opposition by saying he wouldn’t fly around in the aircraft when his term ends. Instead, he said, the plane would be donated to a future presidential library, similar to how the Boeing 707 used by President Ronald Reagan was decommissioned and put on display as a museum piece.