The luxury Boeing 747 presented by Qatar to the U.S. government is standing in San Antonio, Texas, waiting for a special overhaul by defense contractors so President Trump can use it as the next Air Force One.

It's unclear how fast the plane is - a fire Moral, legalbefore Trump travels to the Middle East last week, political and security issues will be prepared with Trump’s boarding the sky.

Once the paperwork covers it, the Air Force will take ownership of the aircraft and the transformation can then begin the transformation, an U.S. official said, without the authority to talk to journalists on the record.

The Air Force did not comment on the plan publicly, and the White House delayed all issues to the Air Force earlier Monday.

"Frankly, the president has nothing to do with that," White House press secretary Karoline Leavitt said on Monday.

When Trump left his trip, Qatar's proposal for the $400 million aircraft was exposed, which brought him to Doha and stopped in Saudi Arabia and the United Arab Emirates. During the trip, Trump said Qatar intends to spend more than $1 trillion on commercial deals with the United States, including Boeing aircraft from Qatar Airways.

The White House said the plane was a gift to the Department of Defense and would pass the legal provisions needed when handing over to the government. Trump said he wouldn't use the plane after leaving the office - although he wanted to park it in the presidential library one day.

"I'm very grateful. I'll never refuse such an offer," Trump said.

Experts say renovating the aircraft will take years of work

But experts say equip such an aircraft to make it suitable for use, as presidential aircraft usually takes at least a few years of work, stripping the aircraft and adding the necessary conditions to make it safe enough to achieve the president.

The timeline means it may not be ready until Trump loses his job. Experts say shortcuts in the transformation can pose national security risks.

“They won’t be able to install the features you normally find on the Air Force.” Richard Aboulafia, Managing Director, Aerodynamic Consultingdescribes a modification schedule that is less than four years old.

“In terms of encrypted communications, electronic warfare, backup power systems, there is nothing in that time frame,” Aboulafia said. “Anyone recommends using a burner phone to see what they say.”

Nicholas Veronico, a former NASA contractor who worked in the 747s and was an author of Air Force One, agreed that shorter time frames would be problematic.

"If the conversion can be done within a year and President Trump is flying around the world in this new Air Force One, he will fly in an eclectic plane. We will put our president in danger," Veronico said.

Members of Congress also issued an alarm, including some of Trump's Republican allies.

“I prefer a large, beautiful aircraft made in the United States, made in the United States, bought in the United States.” Senator Josh Hawley, R-Mo.

Senate Democratic leader Sen. Chuck Schumer proposed banning the Air Force from renovating foreign aircraft into presidential aircraft.

Trump is excited about the criticism, saying it doesn't make sense to refuse gifts.

“Why should our military and our taxpayers be forced to pay hundreds of millions of dollars when they can get it for free from a country that wants to reward us for what we do well. Say on social media.

“Only one fool wouldn’t accept this gift on behalf of our country.”

NPR Tom Bowman and Deirdre Walsh Contributed to this report.