0821 GMT November 30, 2020
Kim made the remarks as he celebrated the 67th anniversary of the end of the 1950-53 Korean War, which fell on July 27, with a reception for veterans, the official KCNA news agency said.
Up to three million Koreans died in the three-year conflict, in which the armistice has never been replaced with a peace treaty, leaving North and South technically still at war, AFP wrote.
The country developed nuclear weapons to win "absolute strength" to stave off another armed conflict, Kim said in a speech, emphasizing the defensive nature of the programs.
"Now we are capable of defending ourselves in the face of any form of high intensity pressure and military threats from imperialist and hostile forces," he said, according to Reuters.
"Thanks to our reliable and effective self-defensive nuclear deterrent, there will no longer be war, and our country's safety and future will be firmly guaranteed forever."
Pyongyang says that it needs its nuclear arsenal to deter against a possible US invasion.
Inter-Korean relations have been in deep freeze for months, following the collapse of a summit in Hanoi between Kim and US President Donald Trump last year.
That nuclear negotiation foundered on what the North would be willing to give up in exchange for a loosening of sanctions.
Kim declared in December an end to moratoriums on nuclear and ballistic missile tests, and Pyongyang has repeatedly said it has no intention to continue talks unless Washington drops "hostile" policies towards the North.