Kim Jong Un has declared his intent to expand North Korea's nuclear arsenal and operational range - calling on the United States to respect his country's nuclear power, in a rare message to Washington.

The United States and North Korea could "get along", Kim added, but only if the US accepts that North Korea's nuclear weapons are here to stay.

His comments, which were made at a five-yearly party congress held in the capital Pyongyang, are seen as leaving a door open to talks with US President Donald Trump ahead of Trump's visit to China in April.

However, Kim dashes hopes of any diplomatic thaw with South Korea, calling them the North's "most hostile entity".

If Washington "respects our present [nuclear] position as stipulated in the Constitution... and withdraws its hostile policy... there is no reason why we cannot get along well with the United States," Kim said at the Ninth Congress of the Workers' Party of Korea, according to state media outlet KCNA.

The future state of US-North Korea relations "depends entirely on the US attitude", Kim said.

"Whether it's peaceful coexistence or permanent confrontation, we are ready for either, and the choice is not ours to make."

He also addressed its neighbour South Korea, saying that it would "permanently exclude Seoul from the category of compatriots", adding that "as long as South Korea cannot escape the geopolitical conditions of having a border with us, the only way to live safely is to give up everything related to us and leave us alone".

One analyst told AFP that Pyongyang's latest remarks signalled "an intention to pursue relations with the US independently, without going through South Korea."

Kim also highlighted Pyongyang's nuclear programme, saying: "We will focus on projects to increase the number of nuclear weapons and expand nuclear operational means."

Despite long-standing international sanctions, North Korea has continued to build its nuclear capabilities, regularly testing banned intercontinental missiles.

State-run KCNA said this week that under Kim's leadership North Korea "radically improved" its "war deterrence", "with the nuclear forces as its pivot".

The secrecy of the regime, however, makes it difficult to evaluate how much progress its military has actually made.

Stockholm International Peace Research Institute (SIPRI), an independent think tank, estimated last year that North Korea had around 50 assembled nuclear warheads and enough fissile material to produce up to 40 more.

Kim also previously called for a "limitless" expansion of the country's nuclear programme in November 2024.

Last year, US President Trump released a global security road map that conspicuously did not mention the denuclearisation of North Korea as a goal - despite that being a constant in the National Security Strategy of every US president since 2003, when Pyongyang's nuclear programme emerged.

The omission fuelled speculation that talks between Trump and Kim, last held in 2019, could soon be revived.

Trump's previous road map, issued during his first term in 2017, mentioned North Korea 16 times - describing it as a threat and a rogue state that could "use a nuclear weapon against the United States".

Kim, however, has long insisted that denuclearisation is not something Pyongyang is considering.

"The concept of 'denuclearisation' has already lost its meaning. We have become a nuclear state," he told parliament in September. "I say 'denuclearisation' is the last, last thing to expect from us."

"If the United States, freeing itself from its absurd pursuit of others' denuclearisation and recognising the reality, wants genuine peaceful coexistence with us, there is no reason for us not to come face to face with it."

Photos from the closing stages of this year's party congress also showed Kim's teenage daughter, Ju Ae, standing alongside her father in a matching black leather jacket at a military parade in Pyongyang.

Earlier this month South Korea's spy agency told lawmakers Kim had selected Ju Ae - who is believed to be 13 - as his heir.

The National Intelligence Service said it would would keep close tabs on whether she attended the party congress.