Video shows North Korea blowing up its Punggye-ri nuclear testing site

North Korean leader Kim Jong Un made good on his promise to demolish his country's nuclear test site, which was formally closed in a series of huge explosions Thursday as a small group of foreign journalists watched.

The explosions at the test site deep in the mountains of the North's sparsely populated northeast were supposed to build confidence ahead of a planned summit next month between Kim and President Donald Trump.

But Trump cancelled the meeting on Thursday, citing "tremendous anger and open hostility" in a North Korean statement released earlier in the day.

The blasts were centred on three tunnels at the underground site and a number of buildings in the surrounding area. North Korea held a closing ceremony afterward with officials from its nuclear arms program in attendance.

The group of journalists that witnessed the demolition, which touched off landslides near the tunnel entrances and sent up clouds of smoke and dust, included an Associated Press Television crew.

North Korea's state media called the closure of the site part of a process to build "a nuclear-free, peaceful world" and "global nuclear disarmament."

"The dismantling of the nuclear test ground conducted with high-level transparency has clearly attested once again to the proactive and peace-loving efforts of the DPRK government being made for assuring peace and stability on the Korean Peninsula and over the world," the North's official news agency reported late Thursday.