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.

Axar.az informs, citing BBC, 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".