Qatar's offer of the jet -- which is valued in the hundreds of millions of dollars -- has raised huge constitutional and ethical questions, as well as security concerns about using an aircraft donated by a foreign power for use as the ultra-sensitive presidential plane.

"The Secretary of Defense has accepted a Boeing 747 from Qatar in accordance with all federal rules and regulations," Pentagon spokesman Sean Parnell said in a statement.

"The Department of Defense will work to ensure proper security measures and functional-mission requirements are considered for an aircraft used to transport the President of the United States," Parnell said, referring questions to the US Air Force.

The US Constitution prohibits government officials from accepting gifts "from any King, Prince or foreign State," in a section known as the Emoluments Clause.

But Trump has denied there are any ethical issues involved with accepting the plane, saying it would be "stupid" for the US government not to take the aircraft.

"It's a great gesture," the 78-year-old billionaire told reporters at the White House last week when asked if the oil-rich Gulf state would expect anything in exchange.

"I would never be one to turn down that kind of an offer. I mean, I could be a stupid person (and) say 'no we don't want a free, very expensive airplane.'"

The leader of the Democratic minority in the US Senate introduced legislation earlier this week that would block Trump from using the aircraft.

Chuck Schumer's Presidential Airlift Security Act would prohibit the Pentagon from using taxpayer funds to retrofit any plane previously owned by a foreign government for use as the presidential plane.

"Donald Trump has shown time and again he will sell out the American people and the presidency if it means filling his own pockets," Schumer said in a statement.

"Not only would it take billions of taxpayer dollars to even attempt to retrofit and secure this plane, but there's absolutely no amount of modifications that can guarantee it will be secure."

Although several Republicans have voiced concerns about the proposed gift, Senate Majority Leader John Thune -- a Trump loyalist -- is not obliged to bring the bill to the floor of Congress's upper chamber.

But Schumer plans to force a vote by offering it as an amendment to spending bills that Republicans will have to pass later in the year.