The declaration came during a full meeting of the central committee of the ruling Worker's Party of Korea -- Kim is its chairman -- giving it significant authority in the North's monolithic society.

The official Korean Central News Agency carried a lengthy report on the meeting Wednesday. Here are some key Kim quotes from the document, and what they could mean:

- Security over sanctions -

"It is true that we urgently need external environment favourable for the economic construction.

"We struggle to direct our efforts to the economic construction owing to the US' gangster-like acts."

Kim acknowledges the impact of sanctions on the North Korean economy, and blames them on Washington.

"We can not give up the security of our future just for the visible economic results and happiness and comfort."

Kim rejects Trump's suggestions that the North will prosper if it denuclearises, epitomised by the video the US president showed the North Korean leader at their first summit in Singapore, featuring high-speed trains and electricity pylons.

"We have to live under the sanctions by the hostile forces in the future, too.

"The victory of the revolution is inevitable but it is not achieved without any difficulties and hardships."

This will be seen as a warning to North Koreans of hard times ahead or limited prospects for economic improvement.

- Moratorium over -

The North has taken "preemptive and crucial measures" to stop nuclear and ICBM tests and close its nuclear testing ground.

But the US, "far from responding to the former with appropriate measures, conducted tens of big and small joint military drills which its president personally promised to stop."

While this avoids explicitly naming Trump, it implies the North considers the US president has acted in bad faith.

The US has also imposed further sanctions on Pyongyang and: "Under such condition, there is no ground for us to get unilaterally bound to the commitment any longer."

"The world will witness a new strategic weapon to be possessed by the DPRK in the near future."

Analysts suggest a solid-fuel intercontinental ballistic missile could be on the agenda. Such a weapon could be launched much more quickly than the North's current liquid-fuelled systems, increasing its military flexibility and reducing the possible time for intervention.

- National pride -

The North's nuclear arsenal contributes to "defending and guaranteeing our sovereignty and right to existence".

The ruling party's claim to legitimacy is rooted in the Korean War, when it and its Chinese and Russian allies fought US-led UN troops to a standstill, in a brutal conflict that technically has never ended. The party says it needs nuclear weapons to deter a possible US invasion.

"The DPRK-US stand-off which has lasted century after century has now been compressed to clear stand-off between self-reliance and sanctions," said Kim. "DPRK" is the short version of the country's official name.

"We should never dream that the US and the hostile forces would leave us alone to live in peace.

"We will never allow the impudent US to abuse the DPRK-US dialogue for meeting its sordid aim but will shift to a shocking actual action to make it pay for the pains sustained by our people."

North Korea was only founded in 1948, but Kim is making a sweeping return to the rhetoric of the past, before the diplomacy of the last two years, when the isolated North was at loggerheads with the US and Seoul and tensions on the peninsula were far higher than today.

- Door still open? -

"The US' real intention is to seek its own political and diplomatic interests while wasting time away under the signboard of dialogue and negotiations and at the same time keep sanctions."

Kim avoids explicitly saying that Pyongyang will not negotiate further, and conditional clauses elsewhere suggest the door is still being held open to further talks.

"If the US persists in its hostile policy towards the DPRK, there will never be the denuclearisation on the Korean peninsula... The scope and depth of bolstering our deterrent will be properly coordinated depending on the US future attitude to the DPRK."

But this indicates that Pyongyang may only be willing to discuss arms control -- the size and power of its arsenal -- rather than denuclearisation. It may also be intended as a signal to a post-Trump administration, with the US president facing an election in November.