Sen. Rand Paul (R-Ky.) expressed concerns about President Trump accepting a luxury Boeing jet from Qatar, suggesting it could potentially undermine the United States’ ability to criticize human rights violations.

“I’ve spent time trying not to sell weapons to Qatar because they have human rights violations of their people,” Paul said in a Monday interview with Fox News host Jesse Watters. “I really haven’t been a big fan, and I wonder if our ability to judge their human rights record would be clouded by the fact of this large gift.”

He added, “I wouldn’t take it. That’s just me.”

The Boeing 747-8 aircraft from the government of Qatar would replace Air Force One and be kept at Trump’s eventual presidential library after his term ends. Boeing has a contract with the U.S. government to build a new Air Force One, but the project has faced delays.

Trump, who was in Qatar on Wednesday, has defended his potential acceptance of the new plane, stating that it would be “stupid” not to take it.

“I could be a stupid person and say, ‘Oh no, we don’t want a free plane.’ We give free things out, we’ll take one too. And, it helps us out because … we have 40-year-old aircraft,” he said Monday morning, referring to Air Force One. “So, I think it’s a great gesture from Qatar, I appreciate it very much. I would never be one to turn down that kind of an offer. I could be a stupid person and say, ‘No, we don’t want a free, very expensive airplane,’ but I thought it was a great gesture.”

Security experts, however, have said accepting a jet from a foreign government that will serve as Air Force One is a huge security risk. They have said the CIA, FBI, and Defense Department will need to go through the aircraft with high-tech gear to ensure there are no tracking devices or other sophisticated monitoring devices on board that would compromise the president and the country.

Rand is not the only Senate Republican expressing unease about the potential arrangement. Although Republicans were initially reluctant to criticize the gift, they have raised concerns for a variety of reasons, The Hill reported.

“I’m not flying on a Qatari plane. They support Hamas,” said Sen. Rick Scott (R-Fla.), an ardent Trump supporter. “I don’t know how you make it safe.”

“‘Gosh, let me give you a plane.’ I mean, that seems pretty nice, but they support Hamas, so I don’t know. I don’t know how you make it safe,” Scott added, but declining to say what he believes Trump should do, as the decision is up to him. “I don’t want the president of the United States flying on an unsafe plane.”

On Monday, Senator John Thune (R-S.D.), the Senate Majority Leader, acknowledged that Boeing is delaying the construction of a new plane but did not fully endorse the offer from Qatar.

“I understand his frustration. They’re way behind schedule on delivering the next Air Force One,” Thune told The Hill. “Whether or not this is the right solution … I don’t know.”

Democrats have swiftly criticized the decision, claiming it represents clear corruption. They argue that accepting the jet would put Trump in violation of the Emoluments Clause, which prohibits federal officials from accepting gifts from foreign countries without congressional approval.

“It’s inappropriate. It’s unconstitutional,” Sen. Jeanne Shaheen (D-N.H.), the top Democrat on the Foreign Relations Committee, told The Hill. “It sends the very worst message to Americans about being in office to enrich himself instead of being focused on what’s in the best interest of the country.”

In his interview with Watters, Paul said he didn’t think accepting the plane was “worth the appearance of impropriety, whether it’s improper or not.”

“I don’t think it’s worth it,” he said, adding he probably wouldn’t ride on the plane if Trump offered.