At last month's inter-Korean summit, Kim also told Moon that he would shutter the site and invite foreign experts and journalists to view the dismantling, South Korea's presidential office said.
"The Nuclear Weapon Institute and other concerned institutions are taking technical measures for dismantling the northern nuclear test ground ... in order to ensure transparency of discontinuance of the nuclear test", KCNA said.
All tunnels at the testing ground in the northeast of the country will be destroyed by explosion, with observation and research facilities also to be removed, along with ground-based guard units.
Recently, in the wake of North Korea's announcement that it would quit its nuclear tests and also shut the nuclear site, it was reported that the hermit kingdom's nuclear site might have partially collapsed last September, making it opt for peace with the global community.
The North Korean foreign ministry said on Saturday that the country was committed to promote close contacts and dialogue with the neighbouring countries and the global society so as to safeguard peace and stability on the Korean peninsula and over the globe.
"In parallel with dismantlement of the nuclear test ground, guards and researchers will be withdrawn and the surrounding area of the test ground be completely closed", the statement said. Earlier this month, North Korean officials asked to start an air route between the Pyongyang and Incheon, South Korea, airspace regions. Trump said in a Twitter posting.
The summit, which has been in the works since Trump accepted Kim's invitation to meet in March, will be the first ever meeting between a sitting U.S. president and North Korean leader.More news: John Legend to Lend His Voice to Google Assistant
However, White House press secretary Sarah Sanders said that she did not believe that Moon would be a part of the historic Trump-Kim summit the following month.
"China welcomes the positive progress made by North Korea and the United States in preparing the leaders' meeting", Geng told reporters at a regularly scheduled briefing.
Chinese geologists believe the mountain over the main site was likely to have collapsed after North Korea exploded its largest ever nuclear weapon a year ago, making it unsafe for further testing and requiring radiation monitoring.
Analysts said the move was positive but limited in its scope.
In June 2008, global broadcasters were allowed to air the demolishing of a cooling tower at the Nyongbyon reactor site, a year after the North reached an agreement with the USA and four other nations to disable its nuclear facilities in return for an aid package.
The North went on to conduct its second nuclear test in May 2009.