Listen to Republican presidential candidate Donald Trump discuss some of his foreign policy positions with The Washington Post editorial board. "NATO is costing us a fortune," Trump said. "We're not reimbursed fairly for what we do." (The Washington Post)

Donald Trump endorsed an unabashedly noninterventionist approach to world affairs Monday during a day-long tour of Washington, casting doubt on the need for the North Atlantic Treaty Organization and expressing skepticism about a muscular U.S. military presence in Asia.

The foreign policy positions — outlined in a meeting with the editorial board of The Washington Post — came on a day when Trump set aside the guerrilla tactics and showman bravado that have powered his campaign to appear as a would-be presidential nominee, explaining his policies, accepting counsel and building bridges to Republican elites.

On Monday night, Trump delivered a scripted address in front of the American Israel Public Affairs Committee, prompting ovations with pledges to stand by Israel and take a hard line on peace talks with the Palestinians.

Trump’s whirlwind day of appearances around the nation’s capital was intended in part to head off an establishment push to deny him the Republican Party’s nomination. But in the Post meeting, the billionaire mogul also made clear that he would not be beholden to the GOP’s long-held orthodoxies.

During the hour-long discussion, during which he revealed five of his foreign policy advisers, Trump advocated a light footprint in the world. In spite of unrest in the Middle East and elsewhere, he said, the United States must look inward and steer its resources toward rebuilding the nation’s crumbling infrastructure.

“At what point do you say, ‘Hey, we have to take care of ourselves?’ ” Trump said in the editorial board meeting. “I know the outer world exists, and I’ll be very cognizant of that. But at the same time, our country is disintegrating, large sections of it, especially the inner cities.”

Trump said U.S. involvement in NATO may need to be significantly diminished in the coming years, breaking with nearly seven decades of consensus in Washington. “We certainly can’t afford to do this anymore,” he said, adding later, “NATO is costing us a fortune, and yes, we’re protecting Europe with NATO, but we’re spending a lot of money.”

‘Be more presidential’

Throughout his unlikely campaign, Trump’s unpredictable, incendiary persona has been his rocket fuel. But with the nomination now within his reach, he is trying at times to round out his sharp edges to convince his party’s leaders — not to mention general-election voters — that he has the temperament and knowledge to be president.

This was one of Trump’s goals as he addressed AIPAC’s annual conference in Washington. For perhaps the first time in his campaign, Trump read from a prepared text on teleprompters — a device he has colorfully mocked other politicians for using.

On Israel, Trump mostly hewed to the party line, giving a full-throated defense of the nation and its interests and arguing that no candidate is a more forceful champion of the Jewish state. His eyes pinging back and forth between the teleprompter screens, Trump embellished his prepared text only to deliver a few criticisms of President Obama and his first-term secretary of state, Hillary Clinton, the Democratic presidential front-runner.

“When I become president, the days of treating Israel like a second-class citizen will end on Day One,” Trump vowed. He received enthusiastic applause from the crowd of thousands, and the much-rumored walkouts during his speech were either called off or went unnoticed in the cavernous Verizon Center arena.

GOP presidential hopefuls John Kasich, Donald Trump and Ted Cruz spoke on March 21 at the AIPAC conference in Washington, D.C. (Peter Stevenson/Reuters)

Earlier Monday, Trump sought to cultivate ties with his party’s establishment at a private luncheon he hosted on Capitol Hill. It was attended by about two dozen Republicans, including influential conservatives in Congress and prominent figures from GOP policy and lobbying circles.

Those with whom he met directly urged Trump to “be more presidential,” according to one attendee. This person, who like others spoke on the condition of anonymity to relate details of the closed session, described it as “a very serious conversation,” adding: “This was the Donald Trump who talks with bankers, not the Donald Trump who is on the stage.”

Trump also sought to showcase his business acumen and dealmaking prowess. He staged an afternoon news conference at the historic Old Post Office Pavilion, which his real estate company is turning into a Trump International Hotel, a few blocks from the White House on Pennsylvania Avenue. The candidate, flanked by employees wearing hard hats, led journalists on a tour of the construction zone.

Trump’s visit to Washington comes amid an intensified effort by some in the Republican establishment, including 2012 presidential nominee Mitt Romney, to deny him the nomination by forcing a contested convention at which the party could rally around an alternative.

At his luncheon meeting, Trump warned party leaders against using parliamentary maneuvers to block his nomination. He later told reporters that he had a productive conversation recently with House Speaker Paul D. Ryan (R-Wis.) and that he has “many millions of people behind me.”

“Now, they can play games, and they can play cute,” Trump said of Ryan and other GOP leaders. “I can only take [Ryan] at face value. I understand duplicity. I understand a lot of things. But he called me last week, he could not have been nicer. I spoke with Mitch McConnell, he could not have been nicer. If people want to be smart, they should embrace this movement.”

Neither Ryan nor McConnell (R-Ky.), the Senate majority leader, attended Monday’s meeting with Trump. It was held at Jones Day, the law firm of Donald F. McGahn, a Trump campaign attorney, and was convened in part by Sen. Jeff Sessions (R-Ala.), a key Trump ally.

Attendees included Heritage Foundation President Jim De­Mint, a former senator from South Carolina and a conservative movement leader, as well as Sen. Tom Cotton (R-Ark.), former House speaker Newt Gingrich (R-Ga.) and former House Appropriations Committee chairman Bob Livingston (R-La.). A group of House members who have endorsed Trump also attended.

“We met with Senator Sessions and some of the great people in Washington,” Trump said. “We had a really good meeting. . . . They can’t believe how far we’ve come because, you know, I think a lot of people maybe wouldn’t have predicted that.”

‘We are a poor country now’

Trump began the day at The Post, where his on-the-record meeting with the editorial board covered media libel laws, violence at his rallies and climate change, as well as foreign policy.

For the first time, Trump listed members of a team chaired by Sessions that is counseling him on foreign affairs and helping to shape his policies: Keith Kellogg, Carter Page, George Papadopoulos, Walid Phares and Joseph E. Schmitz. All are relatively little known in foreign policy circles, and several have ties to the George W. Bush administration.

Trump praised George P. Shultz, who served as President Ronald Reagan’s secretary of state, as a model diplomat and, on the subject of Russia’s aggression in Ukraine, said America’s allies are “not doing anything.”

“Ukraine is a country that affects us far less than it affects other countries in NATO, and yet we’re doing all of the lifting,” Trump said. “They’re not doing anything. And I say: ‘Why is it that Germany’s not dealing with NATO on Ukraine? . . . Why are we always the one that’s leading, potentially, the third world war with Russia?’ ”

While the Obama administration has faced pressure from congressional critics who have advocated for a more active U.S. role in supporting Ukraine, the U.S. military has limited its assistance to nonlethal equipment such as vehicles and night-vision gear. European nations have taken the lead in crafting a fragile cease-fire designed to decrease hostility between Ukrainian forces and Russian-backed separatists.

Trump sounded a similar note in discussing the U.S. presence in the Pacific. He questioned the value of massive military investments in Asia and wondered aloud whether the United States still is capable of being an effective peacekeeping force there.

“South Korea is very rich, great industrial country, and yet we’re not reimbursed fairly for what we do,” Trump said. “We’re constantly sending our ships, sending our planes, doing our war games — we’re reimbursed a fraction of what this is all costing.”

Such talk is likely to trigger anxiety in South Korea, where a U.S. force of 28,000 has provided a strong deterrent to North Korean threats for decades.

Asked whether the United States benefits from its involvement in Asia, Trump replied, “Personally, I don’t think so.” He added: “I think we were a very powerful, very wealthy country. And we’re a poor country now. We’re a debtor nation.”

Jenna Johnson, Paul Kane, Missy Ryan and David Weigel contributed to this report.