North Korea claims to have 'demolished' nuclear test site in presence of foreign journalists

North Korea has carried out what it claims is the demolition of its only nuclear test site in the presence of foreign journalists.

The explosions deep in the mountains of the North's sparsely populated northeast were focused on three tunnels and a number of observation towers in the surrounding area.

The dismantling of the Punggye-ri nuclear site was announced by Kim Jong-un ahead of a planned summit with Donald Trump next month.

The demolition came as the North launched another verbal attack 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 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 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 12 June 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 doesn't 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 program 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. Meeting with the US president as an equal on the world stage would be a major coup for Mr Kim.

Additional reporting by AP.