Nuclear button is always on 'my desk', says Kim Jong-un

North Korean leader Kim Jong-un has warned the United States that 'the nuclear button' is always on his 'desk.'

"The entire mainland of the US is within the range of our nuclear weapons and the nuclear button is always on the desk of my office. They should accurately be aware that this is not a threat but a reality," he said, according to a CNN translation of his speech, during his national New Year's address.

He also declared that North Korea was "a responsible nuclear nation that loves peace" and that "the US cannot wage a war" against it, adding, "As long as there's no aggression against us, we do not intend to use nuclear powers."

Moreover, North Korea's state-run news agency KCNA released a report on Saturday promising that the country would remain committed to its nuclear development in 2018.

"Do not expect any change in its policy. Its entity as an invincible power can neither be undermined nor be stamped out. The DPRK, as a responsible nuclear weapons state, will lead the trend of history to the only road of independence and justice, weathering all tempests on this planet," the report said.

Rising tensions between the US and North Korea, which conducted its largest nuclear test in September and fired off a powerful ICBM in late November, have raised deep concern worldwide.

United States President Donald Trump has long been trading insults with Jong-un over this issue.

While Trump has referred to Jong-un as "rocket man", his rival had previously called him a "mentally deranged dotard.