(CNN) President Donald Trump is open to his eldest son testifying before Congress to address questions about Russian meddling in the 2016 election.

"If he wants to," Trump told reporters traveling on Air Force One Wednesday night when asked if he supported his son testifying.

Trump's comment came as top Republicans and Democrats on Capitol Hill signaled they would likely call on Donald Trump Jr. to testify after the younger Trump disclosed emails showing he was eager to obtain incriminating information on Hillary Clinton from someone described as a "Russian government attorney."

The comment was just one of several the President made Wednesday night on Air Force One during an hour-long conversation with reporters traveling with him to Paris.

The President's stop by the press cabin was initially ruled off-the-record -- a common practice spanning several administrations designed to give reporters insight into the President's thinking -- but the White House agreed Thursday afternoon to put excerpts of the comments on the record after Trump said he wanted them to be publicized.

Here are some of the highlights of the excerpts of his gaggle with reporters aboard Air Force One:

1. Health care is tough ... tougher than Middle East peace?

"I'd say the only thing more difficult than peace between Israel and the Palestinians is health care. It's like this narrow road that about a quarter of an inch wide," Trump said.

Even as he signaled that "I think we're going to get something that's really good," Trump lamented the tricky politics of wrangling 50 Senate Republicans to back the bill to repeal and replace Obamacare making its way through the Senate.

"You get a couple here and you say, 'great,' and then you find out you just lost four over here. Health care is tough," said the President, who is also pushing a Middle East peace initiative.

2. Meeting(s) with Putin

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Trump addressed still-lingering questions about his meeting with Russian President Vladimir Putin on the sidelines of the G20.

But his comments offered little more clarity on whether he accepted the Russian president's denials of Russian government meddling in the 2016 presidential election, which the US intelligence community has ruled a fact.

Putin and his foreign minister claimed that Trump accepted the denials.

On Air Force One, Trump said: "I said to him, were you involved with the meddling in the election? He said, absolutely not. I was not involved. He was very strong on it. I then said to him again, in a totally different way, were you involved with the meddling. He said, I was not -- absolutely not."

Pressed again on whether he told Putin he believed him, Trump offered:

"I asked him, were you involved? He said, very strongly -- said to him a second time -- totally different -- were you involved? Because we can't let that happen. And I mean, whether it's Russia or anybody else, we can't let there be even a scintilla of doubt when it comes to an election. I mean, I'm very strong on that," Trump said. "I said, look, we can't -- we can't have -- now, he said absolutely not twice. What do you do? End up in a fistfight with somebody, OK? Because then I brought up Syria."

Trump also said he likely will invite Putin to the White House -- just not yet.

"I would say yes, yeah. At the right time. I don't think this is the right time, but the answer is yes I would," Trump said.

3. Border wall -- or, perhaps, fence?

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The border wall he has promised his supporters since the very first day of his presidential campaign? It might be more of a fence.

Trump told reporters the wall he plans to build on the southern US border will need to be transparent -- literally.

"One of the things with the wall is you need transparency. You have to be able to see through it. In other words, if you can't see through that wall -- so it could be a steel wall with openings, but you have to have openings because you have to see what's on the other side of the wall," Trump said.

Trump also made clear that the idea he has floated of putting solar panels on the border wall was not a joke.

"No, not joking, no. There is a chance that we can do a solar wall," Trump said. "We have major companies looking at that. Look, there's no better place for solar than the Mexico border -- the southern border. And there is a very good chance we can do a solar wall, which would actually look good. But there is a very good chance we could do a solar wall.

The wall, Trump said, would only need to cover "700 to 900 miles," not the full 2,000 mile-long border. Trump also signaled during the campaign that natural barriers made it unnecessary for the border wall to cover the full length of the US-Mexico border.

4. Steel tariffs?

Photos: Trump in Paris for Bastille Day celebrations US President Donald Trump and first lady Melania Trump board Air Force One at Paris' Orly Airport as they head back to the United States on Friday, July 14. The Trumps attended the Bastille Day parade in Paris at the invitation of French President Emmanuel Macron. Hide Caption 1 of 18 Photos: Trump in Paris for Bastille Day celebrations Macron bids farewell to Trump following the Bastille Day military parade on the Champs-Elysees in Paris. Macron has sought to act as Trump's bridge to Europe, his advisers have said, as other leaders there have isolated the United States on key issues. Hide Caption 2 of 18 Photos: Trump in Paris for Bastille Day celebrations The Trumps join Macron and French first lady Brigitte Macron near the end of the parade on July 14. Bastille Day celebrates the storming of the Bastille military prison in 1789, a key date in the French Revolution. Friday's military display also commemorated the centennial of the US entry into World War I. Hide Caption 3 of 18 Photos: Trump in Paris for Bastille Day celebrations The Macrons play host to the Trumps during the elaborate military display. Hide Caption 4 of 18 Photos: Trump in Paris for Bastille Day celebrations A crowd gathers outside a police cordon below the Eiffel Tower as the two leaders and their wives attend a dinner at Le Jules Verne restaurant on Thursday, July 13. Hide Caption 5 of 18 Photos: Trump in Paris for Bastille Day celebrations The couples dine at the Eiffel Tower restaurant on July 13. Hide Caption 6 of 18 Photos: Trump in Paris for Bastille Day celebrations Trump and Macron hold a news conference after meeting at the Elysee Palace in Paris on July 13. Hide Caption 7 of 18 Photos: Trump in Paris for Bastille Day celebrations The leaders sit across a table at the Elysee Palace. Hide Caption 8 of 18 Photos: Trump in Paris for Bastille Day celebrations The two men have been holding extended talks on security matters, including the civil war in Syria and counterterrorism efforts. Hide Caption 9 of 18 Photos: Trump in Paris for Bastille Day celebrations The first ladies leave a boat after a trip on the Seine River on July 13. Hide Caption 10 of 18 Photos: Trump in Paris for Bastille Day celebrations Tourists take pictures of Melania Trump as she visits the Notre Dame Cathedral on July 13. Hide Caption 11 of 18 Photos: Trump in Paris for Bastille Day celebrations President Macron welcomes Trump before their meeting at the Elysee Palace. Hide Caption 12 of 18 Photos: Trump in Paris for Bastille Day celebrations Trump exits his car as he arrives for the meeting in Paris. Hide Caption 13 of 18 Photos: Trump in Paris for Bastille Day celebrations The Trumps and the Macrons tour Napoleon Bonaparte's tomb on July 13. Hide Caption 14 of 18 Photos: Trump in Paris for Bastille Day celebrations The Trumps and the Macrons attend a welcoming ceremony at Les Invalides, which houses Napoleon's tomb. Hide Caption 15 of 18 Photos: Trump in Paris for Bastille Day celebrations Macron greets Trump at Les Invalides. Hide Caption 16 of 18 Photos: Trump in Paris for Bastille Day celebrations Melania Trump visits with children at Paris' Necker Hospital on July 13. Hide Caption 17 of 18 Photos: Trump in Paris for Bastille Day celebrations President Trump waves as he and his wife arrive at Paris' Orly Airport. Hide Caption 18 of 18

Trump confirmed that he is mulling tariffs on steel imports -- or perhaps quotas.

"Steel is a big problem. Steel is -- I mean, they're dumping steel. Not only China, but others. We're like a dumping ground, OK? They're dumping steel and destroying our steel industry, they've been doing it for decades, and I'm stopping it. It'll stop," Trump said.

"There are two ways," he added. "Quotas and tariffs. Maybe I'll do both."

The comments come as Trump's Commerce Department has been leading an investigation into whether the price of steel imports into the US pose a risk to US national security by limiting domestic production.

5. Trade key as US looks to pressure China on North Korea

In what could be perceived as a warning to China, Trump signaled that he could use the US-China trading relationship as a lever to pressure China into increasing its own pressure on North Korea.

"Somebody said, what cards do you have? I said, very simple -- trade. We are being absolutely devastated by bad trade deals. We have the worst of all trade deals is with China," Trump said. "But the biggest strength we have are these horrendous trade deals, like with China. That's our strength. But we're going to fix them. But in terms of North Korea, our strength is trade."

Trump also made clear he wants to "fix" the US' trade imbalance with China, which enjoys a trade surplus with the US.

6. Donald Trump Jr.

Trump didn't just say he would be open to his son testifying on his meeting with a Russian lawyer last summer, he also offered an extensive defense of his son's actions.

Trump said that the press has been unfairly critical of his son's meeting with a Russian lawyer, whom the younger Trump believed to be a "Russian government lawyer," according to the emails disclosed after The New York Times reported on the meeting.

"Don is -- as many of you know Don -- he's a good boy. He's a good kid. And he had a meeting, nothing happened with the meeting. It was a short meeting, as he told me -- because I only heard about it two or three days ago," Trump said.

"Honestly, in a world of politics, most people are going to take that meeting. If somebody called and said, 'Hey' -- and you're a Democrat -- and by the way, they have taken them -- 'Hey, I have ... some information on Donald Trump. You're running against Donald Trump. Can I see you?' I mean, how many people are not going to take the meeting?" Trump said.