North Korea's position as a nuclear weapons state will remain an undeniable reality as it builds up its forces until military threats from the United States and its allies are eliminated, state news agency KCNA said on Friday.

It was quoting comments by North Korean Foreign Minister Choe Son Hui in a statement criticising the United States and other Group of Seven countries, following a statement at the end of their meeting in Japan on Tuesday.

The G7 foreign ministers had condemned the North's April 13 test of what Pyongyang said was a solid-fuel intercontinental ballistic missile, and urged denuclearisation. Tension has flared as North Korea has ramped up military activities, and threatened “more practical and offensive” action as U.S. and South Korean forces hold annual spring military exercises it called a rehearsal for “an all-out, nuclear war.”

Choe said North Korea's status as a nuclear power was “final and irreversible,” and would stay an“undeniable and stark reality” even if Washington and others in the West denied it.

Pyongyang's development of nuclear weapons is only intended to guard against U.S. threats, she added, telling Washington to drop its “hostile policy” against the North to ensure its own security.

"We will never seek any recognition or approval from anyone, as we are satisfied with our access to the strength for a tit-for-tat strike against the U.S. nuclear threat,” KCNA quoted her as saying. Choe accused the G7 countries of illegally interfering in North Korea's internal affairs by demanding denuclearisation, saying Pyongyang would respond if they attempted to violate its sovereignty and fundamental interests.

"We will continue to take action measures based on all legal rights granted to a sovereign state until the military threat posed by the U.S. and its allied forces hostile toward us is completely removed,” Choe said.

Seoul's unification ministry, charged with handling relations between the neighbours, denounced the North's statement as“far-fetched,” urging it to stop making threats and developing unlawful weapons programmes.

"North Korea will never get what it wants through nuclear and missile development, and it will only become more isolated from the international community,” ministry deputy spokesperson Lee Hyo-jung told a briefing.

Unification Minister Kwon Young-se said it was not possible to rule out a major provocation by North Korea ahead of a U.S. visit next week by the South's president, Yoon Suk Yeol, for a summit with President Joe Biden.