The North's announcement came days after Washington announced that the historic summit between Kim and Trump would be held on June 12 in Singapore.
Friday's statement from the UN's International Civil Aviation Organization (ICAO) followed a visit by its representatives to the North Korean capital, Pyongyang, earlier this week.
It follows a flurry of global engagement with North Korea as the two Koreas held their own summit in late April, and officials plan to hold high-level meetings in coming weeks. "Thank you, a very smart and gracious gesture", he tweeted.
South Korea has said it hopes the summit will lead to "denuclearisation of the Korean Peninsula, as well as permanent peace on the peninsula". However, a final attempt by Bush to complete an agreement to fully dismantle North Korea's nuclear weapons program collapsed that December when the North refused to accept US -proposed verification methods.
In announcing the plan to shut Punggye-ri last month, Kim said North Korea no longer needed to conduct tests because it had completed its goal of developing nuclear weapons.
On Saturday, the country confirmed that it will invite reporters from the United States and South Korea to "ensure transparency of discontinuance of the nuclear test". Date will depend on weather conditions. Last month, South Korean President Moon Jae-in had asked the United Nations to help verify the shutdown.More news: Celtics' title hopes rest on impossible LeBron James task
The historically isolated country also plans to soften air space restrictions and allow more access for foreign media for the destruction of the nuclear site, according to a message carried by North Korean state media.
Punggye-ri has hosted all six of the North's nuclear tests, the latest and by far the most powerful in September previous year, which Pyongyang said was an H-bomb.
During the meeting, Kim promised to dismantle the Punggye-ri underground nuclear test site in northeastern North Korea and transparently show the dismantlement to the world.
But US intelligence officials have said it remains usable and could be reactivated "in a relatively short period of time" if it was closed.
It will involve the removal of all research buildings, observation facilities and security posts. From there, journalists will board a charter train to the test site.
However, he said that sanctions would not be lifted until after a thorough vetting process that guaranteed the nuclear programme had been scrapped.