By Peter Nicholas 

WASHINGTON -- President Trump said that his steel tariffs on China and other countries are rescuing an iconic U.S. industry that was in danger of closing and predicted that the competition U.S. companies will face in the future will mostly be domestic due to his actions.

In an impromptu, 20-minute Oval Office interview Wednesday, Mr. Trump said some people may complain that in the short term steel prices may be "a little more expensive," but that they ultimately will drop and his moves will have preserved an industry important to national security.

Competition will be "internal, like it used to be in the old days when we actually had steel, and U.S. Steel was our greatest company," he said.

Mr. Trump's remarks came on the same day the White House announced he was revoking the security clearance of one of his most vocal critics, former Central Intelligence Agency Director John Brennan. The White House is also trying to contain any damage from publicity surrounding the release of a tell-all book by Omarosa Manigault Newman, a former senior White House official who was fired in December.

In upbeat tones, the Republican president talked about the strong domestic economy and his own political power as he said was demonstrated in GOP primaries throughout the country. He reiterated that he would like to see the investigation into alleged Russian interference in the 2016 presidential race end, but said he is considering giving an interview to the investigator, special counsel Robert Mueller.

"We're looking at it," he said.

Mr. Trump pledged in March to impose global tariffs of 25% on imported steel, and 10% on aluminum, moves he said were based on national security concerns.

The announcement sparked worries of a looming global trade war and prompted retaliation or threats of it across Asia, Europe and elsewhere in North America, elevating tensions between the U.S. and many if its longtime allies.

China, which has come to dominate the global steel market, has responded to the steel tariffs and other trade measures with its own retaliatory trade measures against the U.S.

In what he called a sign that the tariffs are working, Mr. Trump said steel companies are opening new U.S. plants and "our steel industry is one of the talks of the world. It's booming."

Many economists, business leaders, and members of Mr. Trump's own party would take issue with his boasts, arguing that he is both exaggerating the benefits of the policies while understating their significant direct and indirect costs.

While some steelmakers have expanded U.S. production in the wake of the tariffs, other U.S. manufacturers remain heavily dependent on imported metals. Moreover, even the administration's own estimates of the tariffs' impact project a reduction in imports, not their elimination, still leaving significant foreign competition for U.S. makers.

Foreign steel companies make large numbers of specialty products that American ones don't produce, and, experts say, are unlikely to jump into those segments, even with new protections.

Steel users around the country have blamed the tariffs for higher costs, crimped profits and, in some cases, layoffs and production cuts. A Missouri nail company received widespread attention for claiming that higher input costs from the tariffs led to a 70% drop in orders and a 25% cut in its workforce.

Critics also point to the bigger losses that have resulted from retaliatory tariffs by trading partners. Harley-Davidson Inc. has drawn Mr. Trump's ire by complaining publicly about the double-whammy it has suffered. European tariffs on certain American exports have prompted the motorcycle maker to shift production outside the U.S., while it said higher steel and aluminum costs would boost its cost of U.S. assembly by $55 million this year.

On the midterms, the president said his endorsements are making a crucial difference, vaulting GOP candidates to victory in races they were on track to lose had he stayed out.

He expects a strong Republican showing in November, maintaining that the comparatively high percentage of voters who believe the country is on the right track will prevent the sort of sweeping opposition-party victories in past midterms.

Several times Mr. Trump interrupted the conversation to summon aides to the Oval Office to share charts showing his endorsement record and to discuss the size of his following on social media.

"So what's my record?" he asked political director Bill Stepien, who said the president had yet to lose a candidate he has backed in Republican primary races.

Mr. Trump said he notched eight wins out of nine in special elections.

In a special election in Alabama last fall, Mr. Trump endorsed then-incumbent Sen. Luther Strange, who lost to Roy Moore in the Republican primary. Moore went on to lose the general election to Democrat Doug Jones.

Incumbent presidents typically suffer steep losses in their first midterm elections, but Mr. Trump said he expects the party to do "great."

"As long as I can get out and campaign, I think they're going to win, I really do," he said. "It's a lot of work for me. I have to make 50 stops, it's a lot. So, there aren't a lot of people that can do that, physically. Fortunately, I have no problem with that."

He and Mr. Stepien said they were buoyed by a Real Clear Politics average of polling that shows more than 40% of Americans believe the country is moving in the right direction.

Asked if his campaign appearances might also mobilize Democratic voters, Mr. Trump said, "It may -- but it energizes my people much more than it energizes them."

"I think the Democrats give up when I turn out," he said. "If you want to know the truth, I don't think it energizes them. I think it de-energizes them. I think they give up when I turn out."

Asked about the White House decision to yank Mr. Brennan's security clearance and to evaluate the clearances held by others, Mr. Trump said was prepared to do it last week, but it was too "hectic."

Mr. Trump, who was criticized for targeting for security clearance only people who served in Democratic administrations, said he "would put a Republican on, too, if I thought they were incompetent or crazy."

Apart from Mr. Brennan, the president drew attention to former FBI agent Peter Strzok, who had served on the Mueller investigation and was found to have sent anti-Trump messages to his mistress; and also FBI Deputy Director Andrew McCabe, whom Attorney General Jeff Sessions fired in March, alleging he made an unauthorized disclosure to the news media and "lacked candor" in speaking to an internal watchdog -- allegations Mr. McCabe has strongly disputed.

Mr. Brennan in a tweet called the move "part of a broader effort by Mr. Trump to suppress freedom of speech & punish critics" and said it "should gravely worry all Americans, including intelligence professionals, about the cost of speaking out."

Mr. Trump said the Russia probe is unwarranted. "Of course they say it's not an investigation. You know, in theory I'm not under investigation...I'm not a target. But regardless, I think that whole -- I call it the rigged witch hunt, is a sham."

Mr. Trump didn't rule out testifying before Mr. Mueller, but he said the special counsel's investigation has been "so badly discredited."

The Mueller investigation last month indicted a dozen Russian intelligence officers and charged them with hacking the computers of Democratic organizations and ensuring the pilfered information became public.

--Jacob M. Schlesinger and Rebecca Ballhaus contributed to this article.

Write to Peter Nicholas at peter.nicholas@wsj.com

(END) Dow Jones Newswires

August 15, 2018 20:19 ET (00:19 GMT)