US President Donald Trump has scrapped his much-anticipated meeting with North Korean leader Kim Jung-un, warning Pyongyang that the US military is ready to act should it take any “foolish and reckless” action.

In a letter released Thursday night (Wednesday local time), Mr Trump said he had no option but to cancel the June 12 meeting in Singapore in light of North Korea’s return to threats and provocative rhetoric.

Speaking at the White House on Friday (Thursday local time), the President said the decision amounted to a “tremendous setback” for North Korea and the world.

The cancellation of the talks came after a North Korean vice minister of foreign affairs on Thursday described US Vice President Mike Pence as a “political dummy” in the latest of a series of harshly worded statements from Pyongyang.

“Our military, which is by far the most powerful anywhere in the world that has been greatly enhanced recently as we all know, is ready as necessary,” he told reporters.

Despite the tough talk, the President left open the door to renewing the diplomatic thaw of earlier this year.

“If and when Kim Jong-un chooses to engage in constructive dialogue and actions, I am waiting,” he said.

In his letter addressed to Mr Kim, Mr Trump blamed Pyongyang’s “anger and open hostility” for scuttling the talks.

“I was very much looking forward to being there with you,” he wrote.

“Sadly, based on the tremendous anger and open hostility displayed in your most recent statement, I feel it is inappropriate, at this time, to have this long-planned meeting.”

Earlier in the day the White House had indicated a final decision on the summit would not be made until next week, noting that US diplomats and State Department officers were continuing with summit preparations.

The sudden scuttling of the parley suggests Mr Trump has come to believe North Korea is playing a familiar game: extending an olive branch with one hand while making a defiant fist with the other.

Previous presidents also thought they had struck deals with Pyongyang only to learn the North Korean leadership had ignored its part of the pact.

“Please let this letter serve to represent that the Singapore summit, for the good of both parties, but to the detriment of the world, will not take place,” Mr Trump’s letter read, adding an ominous veiled warning:

“You talk about your nuclear capabilities, but ours are so massive and powerful that I pray to God they will never have to be used.”

The conciliatory tone North Korea struck during the recent Winter Olympics has eroded over recent weeks, spurred initially by Pyongyang’s expressions of fury at military exercises in South Korea.

That rancour stepped up a notch when Mr Pence commented in a television interview that North Korea would “end like the Libya model ended” if Mr Kim backed out of the meeting.

Libyan leader Muammar Gaddafi was brutally assassinated after acceding to US demands he dismantle his weapons of mass destruction program.

Choe Son-hui, North Korea’s vice-minister of foreign affairs, branded Mr Pence’s comment as intolerable while the country’s state-run news agency described the Libya comparison as “stupid” and “ignorant” and branded Mr Pence as “a political dummy”.

The Trump administration’s decision to cancel the talks comes less than 24 hours after invited foreign journalists witnessed a series of explosions at the nuclear test site deep in the mountains of the North’s sparsely populated northeast.

While there were no international weapons inspectors on hand to verify the North’s claim, press reports said the blasts shattered three tunnels at the underground site and a number of buildings in the surrounding area.

The 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.

A commuter pauses at a Seoul railway station to watch satellite imagery of the blasts. Photo: AP/Ahn Young-joon

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

By bringing in a small group of television journalists and other members of the news media, the North was likely hoping to stage a propaganda coup – a bid for international headlines and favourable publicity that Mr Trump has now scuttled as well as the Singapore talks.

-with agencies