In a statement carried by state media, North Korea's Foreign Ministry said that all of the tunnels at the country's northeastern testing ground will be destroyed by explosion, and that observation and research facilities and ground-based guard units will also be removed.
A ceremony for the dismantling of the facility has been scheduled between May 23-25, Pyongyang's foreign ministry said, according to the official KCNA news agency.
The Korean Central News Agency (KCNA) reports that journalists from the US, South Korea, China, Russia and the United Kingdom will be invited to observe a ceremony marking the start of the process, which will be held at some point between 23 May and 25 May, depending on weather conditions.
All global journalists will be provided with a charter flight into Wonsan, a port city in eastern North Korea, from Beijing, KCNA said.
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The North Korea-watching 38 North blog said on April 30 that synthetic aperture radar data of the test site corroborates Kim's statement that two tunnels remain viable.
"In parallel with dismantlement of the nuclear test ground, guards and researchers will be withdrawn and the surrounding area of the test ground be completely closed", the statement said.
Kim declared his nuclear force as complete in December, following North Korea's most powerful nuclear test to date in September and three flight tests of ICBMs created to reach the USA mainland.
But sceptics warn that Pyongyang has yet to make any public commitment to give up its arsenal, which includes missiles capable of reaching the United States. "North Korea's nuclear test center will be discarded in order to ensure the transparency of the suspension of the nuclear test".
At a ruling party meeting last month, the North announced that it had suspended all tests of nuclear devices and ICBMs and the plan to close the nuclear test site. For instance, Kim's father Kim Jong Il invited foreign journalists to watch the destruction of a cooling tower at the Yongbyon reactor, where the North produced plutonium, in the summer of 2008.