Researchers say satellite pictures show several buildings near North Korea’s only nuclear test site have been razed.

North Korea has started dismantling its Punggye-ri nuclear test site, according to satellite pictures analysed by experts.

The move comes weeks ahead of a historic meeting between North Korean leader Kim Jong-un and US President Donald Trump during which the two countries will talk about denuclearisation.

A group of researchers from 38 North, an organisation dedicated to analysis of North Korean affairs, compared satellite images from April 20 with pictures taken on May 7.

The images show several buildings near all four entrance tunnels have been completely or partially demolished.

South Korea’s military said on Tuesday that Pyongyang was moving ahead with plans to close its nuclear test site, according to the Associated Press news agency.

Roh Jae-cheon, spokesman for South Korea’s Joint Chiefs of Staff, said South Korea’s military had seen signs that North Korea 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 had seen.

According to the report published on the group’s website, North Korea has also removed some of the mining cart rails used to access the underground part of the site, which is based in the mountainous northern region of North Korea.

But not all buildings have been demolished yet, the researchers concluded.

“Other more substantial buildings around the facility remain intact, including the two largest buildings at the Command Center, and the Main Administrative Support Area,” the researchers wrote.

“Moreover, no tunnel entrances appear to have yet been permanently closed,” they added.

North Korea invites journalists

North Korea has said it will completely dismantle the site, including collapsing the tunnels and blocking the entrances sometime between May 23 and May 25.

“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,” North Korean press agency KCNA said earlier this week.

On Tuesday, North Korea invited eight South Korean journalists to witness that event, according to Yonhap news agency.

Journalists from China, Russia, the United States and the United Kingdom will also attend the event.

North Korean leader Kim Jong-un pledged to close the site during a landmark summit last month with South Korean President Moon Jae-in.

Prior to Kim’s meeting with Moon, the North Korean leader announced on April 21 that all nuclear and missile tests were to be suspended, saying the Punggye-ri site had “finished its mission” after completing its nuclear programme.

But days later, the South China Morning Post newspaper reported that the facility had collapsed, threatening an “unprecedented risk” of radioactive fallout.

The newspaper said the Punggye-ri site, situated near Mount Mantap in northeastern North Korea, was “wrecked” beyond repair by a landslide.

It suggested the incident “may” have been the reason for Kim’s announcement of a suspension in testing.

Six nuclear tests – including North Korea’s most powerful test to date in September 2017 – have been carried out at the facility since Pyongyang began experiments in 2006.

The closure comes shortly before a planned meeting between Kim and Trump in Singapore on June 12.

It will mark the first summit between a sitting US president and a North Korean leader.

Trump is expected to push North Korea to give up its nuclear weapons at the meeting in exchange for the removal of economic sanctions and US assistance in rebuilding Pyongyang’s ailing economy.

South Korea has said it hopes the summit will lead to “denuclearisation of the Korean Peninsula, as well as permanent peace on the peninsula”.

Last month, Kim and Moon pledged to formally end the 1950s Korean War and pursue “complete denuclearisation” of the Korean Peninsula in the first inter-Korea summit since 2007.

The two leaders signed a joint statement that committed both to deepening ties and working towards reunification after the meeting on April 27, which saw Kim become the first North Korean leader to set foot in South Korea since the Korean War, which took place from 1950 to 1953 and ended with an armistice agreement.