The site's closure would set up next month's historic summit between North Korean leader Kim Jong Un and President Donald Trump, which is shaping up to be a crucial moment in the global diplomatic push to resolve the nuclear standoff with the North. Still, analysts say the closure wouldn't represent a material step toward full denuclearization.
Roh Jae-cheon, spokesman for South Korea's Joint Chiefs of Staff, said the South's military has seen signs that the North is conducting "preparatory work" so that it can carry out its plans to shut down its northeastern testing ground. He did not specify what the military has seen.
But an analysis by 38 North, a North Korea-focused U.S. website, said commercial imagery taken last week shows that several operational support buildings have been razed and rails for mining carts have apparently been removed. The site has been used for each of North Korea's six underground nuclear test explosions.
"Commercial satellite imagery from May 7 provided the first definitive evidence that dismantlement of the test site was already well underway," the website wrote. North Korea's Foreign Ministry announced Saturday that it will dismantle the test site between May 23 and 25. To provide transparency, the ministry said journalists from South Korea, the United States, China, Russia and Britain will be invited to observe the destruction of tunnels and the removal of observation and research facilities at the site.
Seoul's Unification Ministry said it was informed by the North on Tuesday that eight South Korean journalists will be invited. The North did not reveal the number of spots it will give to non-Korean journalists, according to the ministry.
The eight South Korean journalists — four each from a wire agency and a broadcaster that have yet to be determined — will take a chartered flight from Beijing to the North Korean coastal town of Wonsan on May 22, the ministry said. The reporters will then be transported by a chartered train to the nuclear test site in Punggye-ri.
Kim has already declared his nuclear weapons and missile program as finished and the nuclear testing site's mission as completed. Some analysts question whether the dismantling of the site is aimed at destroying evidence.
While South Korea's presidential office had said that Kim told South Korean President Moon Jae-in during their summit last month that international experts will be invited to witness the closure, the North's Foreign Ministry statement on Saturday did not include any references to allowing experts at the site.
The two Koreas will hold a high-level meeting Wednesday at a border truce village to discuss setting up military and Red Cross talks aimed at reducing border tensions and restarting reunions between families separated by the Korean War.
Seoul's Unification Ministry said Tuesday that the meeting will discuss ways to carry out peace commitments made during the inter-Korean summit. The discussions may also include setting up working-level talks between the countries' sports officials over plans to field combined teams in some sports at the Asian Games in August.
After their April 27 meeting, Kim and Moon issued a vague vow for the "complete" denuclearization of the Korean Peninsula. They also agreed to stop all hostile acts over "land, sea and air" that can cause military tensions and clashes, establish a liaison office in the North Korean border town of Kaesong, and to resume temporary reunions between war-separated families.
South Korea, which brokered the planned talks between Trump and Kim, says Kim has genuine interested in dealing away his nuclear weapons in return for economic benefits. But there are lingering doubts about whether Kim will ever agree to fully relinquish his nukes. Pyongyang for decades has been pushing a concept of "denuclearization" that bears no resemblance to the American definition, vowing to pursue nuclear development unless Washington removes its 28,500 troops from South Korea and the nuclear umbrella defending South Korea and Japan.