"This is reality, not a threat", Kim said during a televised New Year's Day speech.
Kim, wearing a Western-style gray suit and tie, said in his customary annual address his country had achieved the historic feat of "completing" its nuclear forces and added he has a nuclear button on his desk.
But in a rare move the dictator tempered his bellicose rhetoric with the suggestion he may send a North Korean delegation to the Winter Olympics when they are held in South Korea. "As long as there's no aggression against us we do not intend to use nuclear powers".
"We've got a chance here to deliver some fatal blows to some really bad actors in 2018". If the North Koreans conduct an additional test of a nuclear bomb - their seventh - "I would say 70 percent", he said.
In his interview Sunday, Graham said his prediction on the chance of a war with North Korea is "based on a lot of time with President Trump".
This Nov. 29, 2017, file image provided by the North Korean government on Nov. 30, 2017, shows what the North Korean government calls the Hwasong-15 intercontinental ballistic missile, at an undisclosed location in North Korea.
Russian Federation could be helping North Korea build deadly bombs that coud start World War 3, chilling documents reveal.
South Koreans watch a TV news program showing North Korean leader Kim Jong Un's New Year's speech at the Seoul Railway Station in Seoul, South Korea.
"Do not expect any change in its policy".
"Its entity as an invincible power can neither be undermined nor be stamped out".
But the newly uncovered documents, obtained by the Washington Post, include technical drawings for much more advanced missiles - designs that include deadly features seen in some of the newest missiles in North Korea's expanding arsenal.