WASHINGTON (NYTIMES) - President Donald Trump never tires of pointing out that his predecessors left him the "mess" of a nuclear-armed North Korea - a legacy of errors he vows not to repeat.

But as Trump announced Friday (June 1) that his summit meeting with Kim Jong Un was back on, there were moments when he echoed Bill Clinton in his failed effort to settle another North Korea crisis nearly a quarter-century ago.

Rather than sticking with the demand that North Korea disarm immediately, Trump opened the door to a prolonged freeze on the North's existing nuclear capability, with vague declarations that disarmament will follow. That is essentially the deal Clinton embarked on with Kim's grandfather, Kim Il Sung, in 1994.

Rather than warning that he would keep the younger Kim's feet to the fire with sanctions until he complies, Trump said after meeting in the Oval Office with North Korea's spy chief that he no longer wanted to use the term "maximum pressure", a phrase drilled into the vocabulary of his aides for the past year.

And rather than keeping a single-minded focus on nuclear weapons, Trump suggested that the most tangible outcome of his meeting in Singapore might be some kind of peace agreement to formally end the Korean War - a lofty idea that featured in a 2005 joint statement that inaugurated George W. Bush's failed effort with Kim Jong Il, the current leader's father, to halt the North's nuclear progress.

Such comparisons are always inexact, because Trump has inherited a far more complex, potentially catastrophic, problem than his predecessors faced: a North Korea that has solved the mysteries of manufacturing a nuclear bomb, tested one with 15 times the power of the blast that leveled Hiroshima, and is now on the brink of proving its missiles could reach the continental United States.

Still, if Trump's remarks on Friday are a blueprint for how he plans to negotiate with Kim, they foreshadow a process that would resemble - rather than reinvent - those undertaken by Clinton and Bush.

"This is the way it's supposed to go," said Victor D. Cha, who negotiated with North Korea for Bush and was considered by the Trump administration as ambassador to Seoul.

"The question is: Does Trump understand that this is what has been done in the past - that what he's doing is not big-bang historic?"

In one way, of course, it is big-bang historic: No North Korean leader has ever met an American president as an equal. For Kim, that achievement alone will give the 34-year-old leader incalculable prestige in his broken country. For his part, Trump sees the meeting as a historic opportunity to use his dealmaker's skills and personal connections to bridge gaps that his predecessors could not close.

In the process, Trump is upending the usual sequence of events in diplomacy: beginning with a leader-to-leader summit meeting, and then leaving the details to underlings.

What is most remarkable, however, is that Trump agreed to the meeting on an impulse in March, pulled out of it a week ago after reacting to threats in a North Korean statement, and now has restored it without obtaining, at least in public, even the minimum concessions of the kind that North Korea made a decade ago.

Without question, Trump has gotten further with North Korea than any American president since that time. Until recently, White House officials said that was because of his laser focus on harsh sanctions and his threat to use military force, giving the United States leverage it never had before.

But in the past few days, trying to coax the North Koreans to keep the June 12 meeting on the calendar, Trump now risks making Clinton's mistake: an agreement so thin and slow to execute that Kim may be able to run the play his father and grandfather mastered - giving just enough ground to weaken the sanctions on the North, waiting things out, then looking for a way to resume the fastest-developing nuclear program on earth.

Indeed, Trump appears more willing to make concessions to North Korea than he is to Iran, which has a small fraction of the North's nuclear infrastructure, and no nuclear weapons. That may partly reflect the fact that ending the threat from North Korea is Trump's bid for history, much as Iran was President Barack Obama's bid.

Trump's concessions, some people involved in those past negotiations said, are also a sign that he recognizes the realities of dealing with a suspicious, reclusive government that is wedded to its nuclear shield.

The president's evolution toward a more conventional approach was dictated by events he helped set in motion, Cha said. The diplomatic thaw initiated by Kim and South Korea's president, Moon Jae-in, and endorsed by Trump, has already weakened the sanctions regime he spent more than a year marshaling.

South Korea, China and Russia all seem poised to use the new era to resume trade and economic aid to North Korea - before any agreement by the North to give up anything has been achieved.

"Trump is in a box," Cha said, "because if this doesn't go well, and he wants to go back to sanctions, the South Koreans and Chinese won't go along." Trump seems alert to this danger. He has complained about recent meetings between Kim and leaders from China and Russia, voicing suspicions that those countries could play a spoiler role. While he reiterated his determination Friday to keep up the pressure, he raised questions in the same breath about the depth of his resolve.

"It's going to remain what it is now," Trump said of the sanctions, after seeing off his North Korean guest, Kim Yong Chol. "I don't even want to use the term 'maximum pressure' anymore because I don't want to use that term because we're getting along. You see the relationship." He left unclear whether the change was in the sanctions, or how he described them.

But critics say the president is squandering hard-won leverage, the product of 15 months of diplomacy that obtained the toughest United Nations restrictions on trade in history, as well as pushing China, which was angered by Kim's relentless provocations, to embrace for the first time a strategy of isolating North Korea.

"Trump is gradually being molded into positions that have been tried before, but with none of the leverage that previous administrations worked to build, and which the Trump administration had acquired through 2017," said Daniel R. Russel, who was involved in the Clinton-era negotiations and later advised Obama on North Korea.

In the joint statement it signed with the United States and four other countries in 2005, for example, North Korea said it would give up its nuclear arsenal and join the Nuclear Nonproliferation Treaty as soon as possible.

"Trump apparently just agreed to a summit without any way forward on nuclear weapons or much of anything apart from a commitment to start a process whose purpose for now is 'getting to know you,'" said Christopher R. Hill, who led the negotiations with North Korea for Bush.

Moreover, he has promised to back - but not to finance - exactly the kind of aid to the North that Clinton agreed to in 1994. That accord, called the Agreed Framework, was a document of just a few pages in which North Korea agreed to halt all production of plutonium. In return, it was to receive two light-water nuclear reactors, for electricity generation, and fuel oil from the United States.

Much of the oil was delivered, over congressional objections. The reactors were never built because the Agreed Framework was abandoned by the Bush administration after the North Koreans were caught cheating by creating a secret uranium enrichment program, another pathway to the bomb.

Among the biggest critics of the Clinton agreement was Trump's new national security adviser, John R. Bolton. He has publicly proposed that North Korea follow the path of Libya, and simply turn over all of its nuclear equipment before any sanctions relief. But while Libya had barely any equipment, North Korea has a large arsenal and nuclear infrastructure.

When North Korea lashed out at Bolton, pointing out that Libya's leader, Moammar Gadhafi, was killed less than a decade after he gave up his weapons, Trump quickly disavowed the views of his aide. Bolton was left out of Trump's meeting with Kim's emissary on Friday.

Some former negotiators said Trump had gotten a much-needed education in the complexities of dealing with North Korea. They said his drive for a meeting was still the best hope to avoid war.

"The trick will be to reach agreements that may not be the Libya model of immediate disarmament but that stop, roll back and eventually dismantle North Korean programs in a way that gives us confidence that they aren't cheating," said Joel S. Wit, an expert on North Korea who was involved in diplomacy during the Clinton administration.

"The only way to do that is to meet their concerns on issues like a peace treaty," Wit said. "It's not ideal, but that's what negotiations are about. It's not one side capitulates. It's both sides win."