South Korean President Moon Jae-in wants the United Nations to help monitor North Korea's closing of its Punggye-ri nuclear test facility.
Moon's spokesman said Tuesday the president expressed that hope in a phone call with U.N. Secretary-General Antonio Guterres.
North Korean leader Kim Jong Un pledged to close the test site by the end May.
South Korean officials said Sunday that Kim plans to invite experts and journalists from Seoul and the United States to observe the shuttering of the facility.
The development is part of a wave of diplomacy that has included a summit between Moon and Kim and planned talks between Kim and U.S. President Donald Trump.
Meeting the North Korean leader at the Demilitarized Zone would be "intriguing," Trump told reporters on Monday, hours after he tweeted he would like to hold a summit with Kim at the "Peace House/Freedom House" on the border of the two Koreas.
"We're looking at various countries, including Singapore, and we are also talking about the possibility of the DMZ," Trump said in the White House Rose Garden at the conclusion of a news conference with Nigerian President Muhammadu Buhari.
"Some people maybe don't like the look of that, and some people like it very much," Trump responded to reporters as he prepared to step off the podium outside the Oval Office.
"There's something that I like about it because you're there, you're actually there where if things work out, there's a great celebration to be had on the site not in a third-party country," explained the U.S. president.
While not specifically mentioning other venues besides Singapore and the DMZ, Trump did say "the good news is everybody wants us."
The president said he had just told his new national security adviser, John Bolton, that the United States has never been closer to getting rid of North Korea's nuclear weapons and creating "peace and safety for the world."
Trump described Kim as "very open and very straightforward so far," noting the North Korean leader had halted his nuclear weapons testing and ballistic missile launches.
"He has lived up to that for a long period of time," according to Trump.
North Korea last tested a nuclear device in September of last year, and its most recent ballistic missile test was at the end of November 2017.
"I think the summit will happen, and personally I think it's going to be a success," Trump also told reporters Monday afternoon in the Rose Garden.
Asked to define success, he replied: "You got to get rid of the nuclear weapons.
"If it's not a success, I will respectfully leave," Trump reiterated.
Last Friday, Kim became the first North Korean leader to set foot in South Korea when he crossed the border to shake the hand of South Korean President Moon.
The two leaders agreed to work toward removing all nuclear weapons from the Korean peninsula and vowed to pursue talks that would bring a formal end to the Korean War.
North Korea has in the past made similar commitments about its nuclear program but failed to follow through.
National Security correspondent Jeff Seldin contributed to this report.
