U.S. President Donald Trump's willingness to accept luxury planes from the Qatar royal family has sparked legal criticism of this the largest foreign gift ever made by the U.S. government.

Trump is preparing to accept the Boeing 747-8, which he will then use as Air Force One, four sources familiar with the program told NBC News.

Two sources said that once Trump ends his second term, ownership of the gift is expected to be transferred to the Trump Presidential Library Foundation.

Democratic lawmakers and Trump allies criticized the move harshly, saying the gift’s luxury caused serious legal and moral issues.

"I don't know who needs to hear this, but no, Donald Trump can't accept the $400 million Flying Palace from the Qatar royal family," Senator Vermont Bernie Sanders said on social media platform X.

"It's not only careless corruption, but also blatantly unconstitutional. Congress must not allow such an overly high Clicock administration to proceed," Sanders said.

Meanwhile, Trump's far-right ally Laura Loomer said accepting Qatar's planes would be a "stain" of the Trump administration.

However, in an article on the Truth Society, Trump appears to defend the prospect of Qatar sending planes to his administration.

"So the Department of Defense is getting free gifts from 747 aircraft to replace the 40-year-old Air Force One, temporarily through a very open and transparent deal, thus disturbing the bending Democrats they insist on paying for the plane," Trump said.

When Trump prepares to visit Qatar this week, it is his first major foreign trip in his second term.

Qatar's media attachment Ali Al-Ansari told CNBC that any report that is talented in travel is inaccurate.

"The temporary use of the aircraft is being considered between the Qatar Department of Defense and the U.S. Department of Defense, but various legal departments are still reviewing the matter and no decision has been made yet," Al-Ansari said.

White House press secretary Karoline Leavitt told Fox News she was not worried about Katar looking forward to changing planes, saying they knew Trump “worked only with the interests of the American public.”

"Any gift given by a foreign government is always in full compliance with all applicable laws. President Trump's administration is committed to full transparency," Levitt said in a statement to CNBC on Monday.

The plane will not be submitted to the president this week when Trump is in the region, according to a White House official who was anonymously described the evolving situation.

Senate Democratic leader Chuck Schumer believes that acceptance of such gifts is welcomed by "foreign influence."

Schumer said on X: "Nothing is like the Air Force One 'US First' that Qatar brings you. It's not only a bribe, but also an extra legroom."

Rep. Brendan Boyle (D-PA) told MSNBC's Weekend: Prime Time: "I give Donald Trump credit. He is the greatest monster in American history."

"I know that it may be numb to this, but we can never numb ourselves. Even if the polls show that it is not the most important issue for the minds of most voters, I'm sorry, but right or wrong is still important."

He added: "We have to pursue this legally in the courts and we have to raise awareness among the public. It's absolutely excellent, the level of record we've seen in corruption."