North Korea '˜demolishes' nuclear test site with series of blasts

North Korea has carried out what it said is the demolition of its nuclear test site, setting off a series of explosions over several hours in the presence of foreign journalists.

The nuclear test site in Punggye-ri, North Korea. Picture: DigitalGlobe/AP

The explosions at the site deep in the mountains of the North’s sparsely populated north east were centred on three tunnels into the underground site and a number of observation towers in the surrounding area.

The planned closing was previously announced by leader Kim Jong Un ahead of his planned summit with US President Donald Trump next month.

The demolition came as the North lobbed another verbal salvo at Washington, calling Vice President Mike Pence a “political dummy” and saying it is just as ready to meet in a nuclear confrontation as at the negotiating table.

The North’s decision to close the Punggye-ri nuclear test site has generally been seen as a welcome gesture by Mr Kim to set a positive tone ahead of the summit.

Even so, it is not an irreversible move and would need to be followed by many more significant measures to meet Mr Trump’s demands for real denuclearisation.

By bringing in the foreign media, mainly television networks, the North is apparently hoping to have images of the closing - including explosions to collapse tunnel entrances - broadcast around the world.

The North did not invite international inspectors to the ceremony, which limits its value as a serious concession.

The outburst at Mr Pence, issued in the name of a top Foreign Ministry official, comes on the heels of another sharp rebuke of Mr Trump’s newly appointed national security adviser John Bolton, and has raised concerns that a major gap has opened between the two sides just weeks before the June 12 summit in Singapore.

In both cases, Pyongyang was trying to push back against hard-line comments suggesting North Korea may end up like Libya if it does not move forward quickly and irreversibly with concrete measures to get rid of its nuclear weapons.

Choe Son Hui, a vice minister of foreign affairs, was quoted by the North’s state-run news agency slamming as “ignorant” and “stupid” comments Mr Pence made in an interview with Fox News that compared the nuclear-capable North to Libya.

Libya gave up its programme at an early stage only to see its longtime dictator overthrown and brutally killed years later.

The summit plan has hit a number of speed bumps recently as both sides have begun trading barbs and taking tougher positions.

Mr Trump met with South Korean President Moon Jae-in on Tuesday at the White House for consultations and suggested the summit could be delayed or even called off entirely.

Even so, both sides still seem to want to hold the meeting, which would be unprecedented.

Success in talks would be a huge accomplishment for Mr Trump, while meeting with the US president as an equal on the world stage would be a major coup for Mr Kim.