A U.S. F-35 stealth fighter is seen during the press day of the 2017 Seoul International Aerospace and Defense Exhibition at Seoul Airport in Seongnam, South Korea, Monday, Oct. 16, 2017.
North Korea on Monday told the United Nations that it will never negotiate the dismantling of its nuclear weapons unless the United States reverses its "hostile" policy.
However he did warn that the United States mainland was within missile firing range, according to reports.
He warned that "the entire continental territory of the United States is in the reach of our fire" and that if the U.S. undertake an invasion, "they will not be able to escape our strict punishment anywhere in the world".
Kim said North Korea will not target any country that does not join a US-led military campaign.
He pointed to large-scale military exercises every year using "nuclear assets" and said what is more unsafe is what he called a USA plan to stage a "secret operation aimed at the removal of our supreme leadership".
The US Under Secretary of State, John Sullivan, met his Japanese counterpart, Shinsuke Sugiyama, and told reporters that the State Department was still focusing on diplomacy to eventually denuclearise the Korean Peninsula.
US President Trump has also threatened to "totally destroy" North Korea, describing Kim as a "rocket man".
Kim's speech follows escalating threats between North Korea and the United States, and increasingly tough U.N. sanctions.
The sanctions add three more top North Korean officials and six businesses to a blacklist banning them from travel to the European Union and freezing their assets.
An alternative might be for the United States to draw a bright line, requiring verifiable information that a nuclear attack has occurred, before nuclear weapons would be used.