Sen. Rand Paul, R-Ky., said he has doubts over President Donald Trump's willingness to accept a luxury jet from Qatar on behalf of the administration that he hopes to use as Air Force One, but that there are ways the administration could receive it without raising potential conflicts of interest.

"There's a lot of ways this could be arranged, but I think what sent up signals that people were concerned about was that it was going to be temporarily part of the government, and then it was going to the president's library when the president retires. So I think all of those things could be fixed, could be corrected. There probably is a perfectly legal way, but right now, it's raised more questions than I think it's worth," Paul said Sunday to ABC News' "This Week" co-anchor Jonathan Karl.

Paul claimed that the questions that the jet raised overshadowed an otherwise successful trip.

"I think my fear is that it detracts from a largely successful trip where the president is talking about opening up and doing more trade with the Middle East, which is a good thing, particularly amidst all the protectionism and directing away from trade that we've had going on," Paul said.

Trump recently returned from his first major foreign trip to the Middle East. Qatar, one of the nations Trump visited, proposed offering the administration a luxury jet as a gift before the trip, as ABC News first reported. Trump expressed interest in accepting the gift, which did not take place during the trip, raising concerns of potential conflicts of interest. Trump claimed that the approximately $400 million jet would be a gift to the United States government and would be retrofitted to be Air Force One until the end of his term.

Special envoy to the Middle East Steve Witkoff said Sunday that the proposed Qatari plane falls within the laws of the U.S.

"It's a perfectly legal transaction. It's been vetted by the White House counsel, by the Justice Department. There are outside law firms involved. So, it's a perfectly legal, government to government, Department of Defense, to Department of Defense transaction that happens in the normal course and has been happening in the normal course throughout -- throughout our existence. Governments exchange services," said Witkoff.

Here are more highlights from Paul's interview:

Karl: Okay, Senator, let me turn to tariffs. The president also announced a temporary reduction to those big China tariffs, although still 30 percent tariffs on goods coming in from China as he negotiates -- tries to negotiate a new deal, Walmart has warned that this will result in higher prices. What's your assessment?

Paul: Well, tariffs are taxes, and when you put a tax on a business, it's always passed through as a cost, so there will be higher prices. And I think this is what's important to know people talk about, oh, this is America versus China. The U.S. doesn't trade with China. You trade with Walmart, or you trade with Target, or you trade with Amazon. Americans go in and buy a product. Now it might come from China, but think about it this way. Think of the entire trade with China was all TVs. A million people go to Walmart. They all buy a TV. They like the quality, they like the price, and it happened to come from China. But then you draw a circle around China and the U.S., you say, 'Oh my goodness, it's a trade deficit.' We buy all of our TVs from over there, but each individual transaction, each individual who bought a TV was happy. But how can you draw a circle around a million happy people and say they all got ripped off? So there's an economic fallacy here. And the fallacy is that trade deficits actually mean anything. They're an artificial accounting. The only trade that means anything is the individual who buys something. That's the only real trade, and that, by very definition, if it's voluntary, is mutually beneficial or the trade doesn't occur.

Karl: So the actual trade deficit with Canada is actually a little less than, or quite a bit less than, $100 billion, but, but even so is a trade deficit subsidizing Canada?

Paul: No, they're, they're really not related at all. What happens if we trade with another country because they have less expensive goods, is we become richer. You also have more money that you can spend. So let's say you're an average American. You shop at Walmart, you save about $4,000 or $5,000 a year because you're able to purchase goods that are important from other countries. What do you do with that? I don't know. Maybe you go to Disney World. Maybe you go to Dollywood. You know, you go you can you spend a lot of it in America. Maybe you get somebody to cut your grass. There's all kinds of things that happens to that extra money, but you are richer because you've gotten a product at a lower cost. And this is what the marketplace does. It drives prices down and it pushes efficiency. But it isn't one country against another. All of that is in artificial accounting. Paul on trade deficit

Karl: And before you go, there are several lawsuits challenging these tariffs. The Constitution clearly gives Congress the power to impose taxes, to impose duties. What is your -- are these tariffs legal? Do you think these laws -- do you think they'll be get knocked down? And will Congress -- as you suggested -- will Congress grow a spine and assert its control over taxation?

Paul: I think a strict interpretation of the Constitution says that taxes originate in Congress, and more specifically, taxes originate in the House. They have to start in the House first before they come to the Senate. Now we do have a long history, though, of both parties abdicating the responsibility on tariffs and granting power to Congress, which brings up another Constitutional question: can Congress delegate powers given in under the Constitution to the president? In the past, the court has allowed these things, but I think it will be an interesting thing, because most tariffs in our history have been passed by Congress. We've never had widespread tariffs that have been done by fiat by a president, and I object to that.