In the letter, addressed to North Korea's Kim, Trump said, '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 move undercuts some of the optimism after Kim agreed to discuss his nuclear weapons program in a first-of-its-kind summit with Trump on June 12 in Singapore
The pledge to halt the development of nuclear weapons would mean a significant reversal for the young leader
North Korea will participate in the 2020 Summer Games in Tokyo and the 2022 Winter Games in Beijing
North Korea and South Korea will hold a summit at the end of April along the border
The delegation will focus on talks on resuming dialogue between the North Korea and the US
Pyongyang has frequently said it is willing to talk without preconditions, but Washington says it must first take concrete steps towards denuclearisation
Meanwhile, the State Department said there is no plans for the US officials to meet the North Korean delegations during the Winter Olympics in South Korea
The latest drill in Tokyo attracted some protests
North Korea had earlier warned that the US was preparing to ignite another war crisis during the Pyeongchang Winter Olympics
Kim said it is imperative to lower military tensions on the Korean peninsula and improve ties with the South, adding the path to dialogue was open
The Panamanian tanker was banned from leaving port following a government meeting on December 21
The North often lashes out at the annual military drills between the United States and South Korea
According to the North Korean regime, it was now capable of carrying a large nuclear warhead and reaching all US territory
The United States has been in negotiations with China, Pyongyang's ally, on slapping new sanctions on North Korea
However, the South Korean troops have detected 'no unusual movements' of the North Korean Army
Pyongyang 'will march forward and make great advancement victoriously as world's most powerful nuclear and military state'
Minor tremors have been detected after the North carried out its sixth and most powerful nuclear test underground in Sept
North Korea successfully fires Hwasong-15 missile
President Trump said this should have happened a long time ago