U.S. President Donald Trump on Thursday canceled 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, just hours after North Korea demolished its nuclear test site in front of international journalists.
Trump said in the letter it was "inappropriate" to have the June 12 meeting in Singapore.
"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," 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."
Trump appeared to be referring to Thursday's statement in which the North called U.S. Vice President Mike Pence a "political dummy" and lambasted him for his "ignorant and stupid" remarks about North Korea.
"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. "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 later warned North Korea against "foolish or reckless" acts, saying the U.S. will never compromise its safety and security.
"Our military, which is by far the most powerful anywhere in the world, that has been greatly enhanced recently, as you all know, is ready if necessary," he said at a bill signing ceremony at the White House.
At the Pentagon, an official told reporters the U.S. military stands ready to respond to any "provocative actions" from the North.
Trump still promised a brighter future for North Korea should Kim choose to engage in "constructive dialogue and actions." And he said the summit could happen later if the conditions are right.
"I am waiting," he said. "In the meantime, our very strong sanctions, by far the strongest sanctions ever imposed, and maximum pressure campaign will continue as it has been continuing."
Trump added that he believes Kim wants to do "what's right."
Trump and Kim agreed to the meeting in March after the North Korean leader expressed a commitment to dismantling his nuclear weapons program. The diplomatic breakthrough followed months of tensions over North Korea's testing of nuclear weapons and ballistic missiles capable of reaching the U.S. mainland.
South Korean President Moon Jae-in, who had engineered the unprecedented U.S.-North Korea summit, met with Kim in April to lay the groundwork for the Singapore meeting.
North Korea also released three American prisoners in what was seen as a demonstration of its seriousness about improving ties with the United States.
"We were informed that the meeting was requested by North Korea, but that to us is totally irrelevant," Trump wrote. Kim's invitation to a summit had been conveyed by South Korean officials who met with the leader in Pyongyang. "I was very much looking forward to being there with you."
Pyongyang started to issue a series of warnings last week. It called off high-level inter-Korean talks over joint military exercises between South Korea and the U.S. and threatened to pull out of the summit over U.S. calls for "unilateral" denuclearization. The regime took particular offense at talk of Libya-style denuclearization, which would see the regime give up its nuclear weapons program before getting sanctions relief. It also expressed an aversion to meeting the same fate as toppled Libyan leader Muammar Gaddafi.
"I felt a wonderful dialogue was building up between you and me, and ultimately, it is only that dialogue that matters," Trump continued. "Some day, I look very much forward to meeting you."
Trump thanked Kim for the prisoners' release earlier this month, calling it a "beautiful gesture" that was very much appreciated.
"If you change your mind having to do with this most important summit, please do not hesitate to call me or write," he said. "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."
In Seoul, Moon called an emergency meeting with his top security officials.
"Denuclearization of the Korean Peninsula and the establishment of permanent peace are historic tasks that can neither be abandoned nor delayed," he said, expressing hope that Trump and Kim will have "more direct and close dialogue."