Trump's advisers, especially National Security Adviser John Bolton, are unlikely to view the pledges as sufficient to reengage the regime in negotiations, according to Will Saetren, a research associate at the Institute for China-American Studies.

"But at the end of the day Trump is the only person who matters, and Kim knows it," he wrote in an email to Yonhap. "Trump will be eager to build on the positive optics that came out of the inter-Korean summit."

Video images of Moon and Kim's third meeting showed the two leaders beaming as they rode through a parade in Pyongyang in a sunroof-fitted car. They toasted at a banquet and watched large-scale performances before heading together to a legendary mountain on North Korea's northern border

"We might even see a spur of the moment invitation to the White House, but it's hard to tell with this president," Saetren said.

The speculation is that Trump will invite Kim to Washington in October ahead of the critical midterm elections in November.

He has expressed a willingness to meet Kim again, including at the White House, and when asked Wednesday if the two will be meeting soon, he responded, "We will be."

Daryl Kimball, executive director of the Arms Control Association, acknowledged that North Korea did not commit to provide an inventory of its nuclear arsenal, a longstanding demand from Washington.

"But if Kim is willing to pursue the verified decommissioning of the Yongbyon nuclear complex, and any other secret uranium enrichment sites, in exchange for corresponding US steps to reduce tensions, that would be a major step forward because it would halt most of North Korea's fissile material production," he told Yonhap in an email.

Citing North Korea's demand to jointly end the 1950-53 Korean War, which ended only with an armistice, he added, "The ball now is in President Trump's court about whether he will agree to joint political declaration on end of Korean War in order to move the stalled denuclearization process along."

 Signaling Trump's go-ahead, US Secretary of State Mike Pompeo issued a statement Wednesday welcoming Kim's commitments and declaring an intention to "immediately" engage in talks with North Korea.

Pompeo said the US has invited North Korean officials to meet with the new US special representative for North Korea, Stephen Biegun, in Vienna, Austria, "at the earliest opportunity."

He also said he has invited North Korean Foreign Minister Ri Yong-ho to meet with him in New York next week, on the sidelines of the United Nations General Assembly.

But skepticism remains about whether a second summit will materialize.

"It is very hard to predict what President Trump will do. But the people who work with him are unlikely to pursue a second summit with Kim Jong-un before Kim starts actually denuclearizing -- otherwise, a second summit could well be a serious failure for President Trump," Bruce Bennett, a senior defense analyst at the RAND Corp., said.

"Unless North Korea surrenders some nuclear weapons and really does begin to dismantle the Yongbyon complex (I would recommend starting with the uranium enrichment facility), I think President Trump's advisors will likely recommend against a second summit -- it would be too risky." (Yonhap)