U.S. President Donald Trump has agreed to meet with North Korean supreme leader Kim Jong-un by May, setting the ground for a first-ever summit that comes as the isolated Asian state shows new willingness to discuss its nuclear program.

Mr. Kim has “expressed his eagerness to meet President Trump as soon as possible,” South Korean national security adviser Chung Eui-yong said on Thursday evening outside the White House after briefing the U.S. President.

“President Trump appreciated the briefing and said he would meet Kim Jong-un by May to achieve permanent denuclearization.”

Mr. Trump took to Twitter to confirm his acceptance of the offer, adding that he would keep sanctions in place for now.

“Kim Jong Un talked about denuclearization with the South Korean Representatives, not just a freeze. Also, no missile testing by North Korea during this period of time,” the President tweeted a little more than an hour after Mr. Chung’s shock announcement.

“Great progress being made but sanctions will remain until an agreement is reached. Meeting being planned!”

It would be the first between a sitting U.S. president and a North Korean leader – a summit likely to be of potent political value to both sides as they look to cement their standing at home, even as skeptics suggest Mr. Kim may have no intention of laying down his hard-won nuclear arms any time soon.

White House spokeswoman Sarah Sanders said in a statement that “all sanctions and maximum pressure must remain” until North Korea denuclearized. “In the meantime, all sanctions and maximum pressure must remain.”

The South Korean delegation that came to Washington after spending two days earlier this week in Pyongyang echoed that sentiment.

“The Republic of Korea, the United States and our partners stand together in insisting that we not repeat the mistakes of the past and that the pressure will continue until North Korea matches its words with complete actions,” Mr. Chung said, using South Korea’s official name.

North Korea has in the past agreed to denuclearize, only to fail to uphold some of its commitments. Despite outward signs of an extraordinary shift from Pyongyang, some observers caution that Mr. Kim is unlikely to make any rapid moves toward dismantling his nuclear capabilities even if he professes a broad commitment to the notion of denuclearization.

Even so, the agreement to a leaders’ meeting with the United States stands as “a big opportunity to really change the course of history on the Korean Peninsula,” said Joel Wit, a senior fellow at the U.S.-Korea Institute at the Johns Hopkins School of Advanced International Studies.

“This is an extraordinary moment here,” said Carla Robbins, a national security expert at the Council on Foreign Relations. “A few weeks ago, we were threatening war. And now, at least according to South Korea, not only is North Korea inviting Trump to a meeting, but they have said they are going to discuss denuclearization. I’m sort of stunned by this.”

Mr. Kim is also expected to meet South Korean President Moon Jae-in late in April. Japanese Prime Minister Shinzo Abe applauded the “change” in North Korea’s posture and said he intended to travel to the United States to meet Mr. Trump in April to discuss North Korea.

Mr. Chung credited the U.S. President with preparing the ground for this moment, saying “his leadership and his national pressure policy together with international solidarity brought us to this juncture.” For South Korea, he said, “along with President Trump, we are optimistic about continuing a diplomatic process to test the possibility of a peaceful resolution.”

Mr. Kim also told the South Korean delegation “he understands that the routine joint military exercises between the Republic of Korea and the United States must continue,” Mr. Chung said, clearing one potential obstacle to talks, as those military exercises typically take place in spring.

North Korea has yet to discuss its own commitments. And skeptics cautioned against expecting rapid change – or perhaps even much change at all – with North Korea’s nuclear weapons program.

“Kim Jong-un himself said very clearly that the mission for 2018 is to mass-produce nuclear warheads and missiles,” said Tong Zhao, a fellow in the Nuclear Policy Program at the Carnegie-Tsinghua Center for Global Policy. “So they have decided to stop testing. They have decided to stop making quality advancement. But their focus has shifted to making their existing technology operational.”

As part of a second phase of nuclear development, “their main objective is to make the international community, including the United States, accept their new reality.”

Nothing would communicate that acceptance more powerfully than a meeting between Mr. Trump and Mr. Kim, who is likely to want it to take place on North Korean soil – although observers said a more plausible location would be in South Korea, such as the southern Jeju Island.

“The meeting of the two leaders itself gives North Korea something that is dearly important to them and after North Korea achieved its nuclear deterrent capability, that meeting means something even more. It means the U.S. is okay to deal with North Korea, even if North Korea is nuclear-armed,” Dr. Zhao said.

It is not clear what role sanctions played in bringing North Korea to this moment.

“The North Koreans may have reached the end of what they think they need to do to develop nuclear weapons and missiles,” said Mr. Wit, who notes that North Korea began signalling a desire for diplomacy in the fall of 2017.

“Every country asks itself, how much is enough? And they may have decided we have enough, now we need to improve the external security environment.”

Even if Mr. Kim agrees to eventual denuclearization, that is a goal far removed from taking immediate or concrete steps toward renouncing a weapons capability he has spent heavily to achieve. North Korea’s definition of denuclearization may differ substantially from that of the international community.

Han Seung-joo, formerly a South Korean foreign affairs minister and an ambassador to the United States, laid out one potential outcome: North Korea agrees to abandon its intercontinental ballistic missile program and “Trump approves some kind of nuclear status quo.”

In other words, North Korea keeps its nuclear devices but gives up the ability to fire them at the United States. Such a deal would make the word “denuclearization” into “both a euphemism and a fig leaf that both sides can use to their own convenience,” Mr. Han said.

Dr. Robbins, too, sounded a note of caution: The North has previously made commitments to give up its nuclear ambitions – most notably during a deal with the Clinton administration in the 1990s – only to return to producing the weapons.

“Again and again and again, they’ve made commitments and backed away from them,” she said. “We have been here before.”

And Mr. Trump’s administration may not be equipped for such a task. It has no ambassador in South Korea, Dr. Robbins pointed out, making it harder to discern Pyongyang’s intentions or set its own red lines.

“They are so incredibly ill-prepared to conduct a major diplomatic negotiation,” she said. “But this is a hell of a lot better than a Twitter war.”

The Globe and Mail, March 8, 2018