WASHINGTON — US President Donald Trump on Thursday cancelled a planned summit with North Korean leader Kim Jong Un, citing the latter’s "tremendous anger and open hostility."

Trump informed Kim of the cancellation in a letter released by the White House.

"We greatly appreciate your time, patience, and effort with respect to our recent negotiations and discussions relative to a summit long sought by both parties, which was scheduled to take place on June 12 in Singapore," the letter said.

"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."

He did not say which statement he was referring to, but last week Pyongyang started to issue a series of written warnings against US calls for "unilateral" denuclearisation. The regime took particular offense at talk of a Libya-model for denuclearisation, which would see the regime give up its nuclear weapons programme before getting sanctions relief.

"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," Trump wrote in the letter. "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."

Trump said he was looking forward to meeting Kim and felt a "wonderful dialogue" was building up between them.

"Some day, I look very much forward to meeting you," he wrote. "If you change your mind having to do with this most important summit, please do not hesitate to call me or write. The world, and North Korea in particular, has lost a great opportunity for lasting peace and great prosperity and wealth. This missed opportunity is a truly sad moment in history."

Trump still thanked Kim for releasing three American prisoners earlier this month, calling it a "beautiful gesture" that was very much appreciated.

’Deeply concerned’

UN Secretary-General Antonio Guterres on Thursday said he was "deeply concerned" as US President Donald Trump cancelled a widely anticipated nuclear summit next month with North Korean leader Kim Jong Un.

"I am deeply concerned by the cancellation of the planned meeting in Singapore between the President of the United States and the leader of the Democratic Peoples Republic of Korea," Guterres said as he presented a new UN disarmament agenda in Geneva.

"I urge the parties to continue their dialogue to find a path to a peaceful and verifiable denuclearisation of the Korean peninsula," he added.

Trump and Kim had been due to hold high-stakes talks on June 12 aimed at ridding the reclusive state of nuclear weapons, but the meeting was recently thrown into doubt as both sides raised the prospect of scrapping the discussions and traded threats.

Trump’s letter came a day after North Korea attacked US Vice President Mike Pence as "ignorant and stupid."

The decision came as North Korea said it had "completely" dismantled its nuclear test site, in a carefully choreographed move portrayed by the isolated regime as a goodwill gesture ahead of the Singapore summit. — YONHAP/AFP