WASHINGTON: South Korea said Sunday that North Korean leader Kim Jong Un plans to shut down the country’s nuclear test site in May and reveal the process to experts and journalists from the United States and South Korea.

Kim made the comments during his summit with South Korean President Moon Jae-in on Friday, according to Seoul’s presidential spokesman Yoon Young-chan.

Yoon said Kim also said President Donald Trump will learn he’s “not a person” to fire missiles toward the U.S.

Yoon said North Korea also plans to readjust its current time zone to match the South’s. The North in 2015 created its own “Pyongyang Time” by setting the clock 30 minutes behind the South.

Trump and Defense Secretary Jim Mattis spoke on Saturday with their South Korean counterparts after the historic meeting between the leaders of the two Koreas, and Trump said “things are going very well” as he prepares for the expected summit, which he predicted will take place “over the next three or four weeks.”

Mattis and Defense Minister Song Young-moo said they were committed to “a diplomatic resolution that achieves complete, verifiable and irreversible denuclearization” of the North, according to the Pentagon’s chief spokeswoman, Dana W. White.

Mattis also reaffirmed “the ironclad U.S. commitment” to defend its ally “using the full spectrum of U.S. capabilities.”

Trump tweeted Saturday that he had “a long and very good talk” with Moon. He also said he updated Japan’s prime minister, Shinzo Abe, about “the ongoing negotiations” for an anticipated summit with Kim, tentatively set for May or early June.

Moon and Kim have pledged to seek a formal end to the Korean War, fought from 1950 to 1953, by year’s end and to rid the Korean Peninsula of nuclear weapons. Trump has said he’s looking forward to the meeting with Kim and that it “should be quite something.”

“Things are going very well, time and location of meeting with North Korea is being set,” Trump tweeted. A statement from the White House describing the call between Trump and Moon also referred to the North’s future being contingent upon “complete, verifiable, and irreversible denuclearization.”

Trump is claiming credit for the Korean summit, but he now faces a burden in helping turn the Korean leaders’ bold but vague vision for peace into reality after over six decades of hostility.

The North had already called a halt to nuclear and long-range missile tests, which helped dial down tensions significantly.