North Korea has said that it would put all its nuclear facilities – including its operational uranium-enrichment programme and its reactors mothballed or under construction – to use in expanding its nuclear weapons arsenal, sharply raising the stakes in the standoff with the US and its allies.

The decision will affect the role of the North’s uranium-enrichment plant in the North’s main nuclear complex in Yongbyon, north of the capital, Pyongyang, a spokesman for the nuclear department told the Korean Central News Agency. It was the first time North Korea said it would use the plant to make nuclear weapons. Since first unveiling it to a visiting US scholar in 2010, North Korea had insisted that it was running the plant to make reactor fuel to generate electricity, though Washington suggested that its purpose was to make bombs.

Saying “work will be put into practice without delay,” the spokesman also said North Korea would refurbish and restart its mothballed nuclear reactor in Yongbyon. The five-megawatt graphite-moderated reactor had been the main source of plutonium bomb fuel for North Korea until it was shut down under a short-lived nuclear disarmament deal with the United States in 2007. North Korean engineers are believed to have extracted enough plutonium for six to eight bombs – including the devices detonated in 2006 and 2009 in underground nuclear tests – from the spent fuel unloaded from the reactor.

Torrent of threats

Kim has recently raised tensions with a torrent of threats to attack the US and South Korea with pre-emptive nuclear strikes. But this week, he appeared to shift his tone slightly by reiterating that his nuclear weapons were a deterrent that helped his country focus on the more pressing domestic issue of rebuilding the economy.

Even so, a restarting of the reactor and weapons-producing role for its uranium-enrichment plant would add to growing US concern over the North’s nuclear weapons program. The developments mean that the North would now have two sources of fuel for atomic bombs – plutonium and highly enriched uranium – and that Kim could become more strident in his demands.

China’s official Xinhua news agency issued comments from Deputy Foreign Minister Zhang Yesui that did not expressly single out North Korea but nonetheless signalled deepening worry about its actions and the response from the United States and its allies. Zhang told Xinhua that he had met with diplomats from the countries concerned and “expressed grave concern over current developments.” The report did not identify those countries.

In Kim’s speech before the party meeting, the script of which was published in the North Korean newspaper Rodong Sinmun, he said making the country’s possession of self-defence nuclear weapons ‘permanent’ was essential to ensuring that the country could focus on rebuilding its economy.

“Now that we have become a proud nuclear state, we have gained a favourable ground from which we can concentrate all our finance and efforts in building the economy and improving the people’s lives based on the strong deterrent against war,” Kim said, underscoring what his regime has long defined as the fruit of its “military first” policy. “He is chasing after two rabbits at the same time,” said Kim Yong-hyun, a North Korea specialist at Dongguk University in Seoul. “On one hand, he is calling for nuclear armament. On the other hand, he is telling his people that his nuclear weapons will bring about economic dividends.”

North Korea used the perceived threats from the United States, like its joint military drills with South Korea, to justify its nuclear weapons arsenal. The North’s new party line removed any lingering “ambiguity” over what North Korea might try to do with its nuclear weapons, said a senior South Korean government official, who briefed a group of foreign reporters on President Park Geun-hye’s policy on North Korea on condition that he remain unnamed. “We now know their real intention,” he said.

“The picture is clear. What we will do is the combined will of the international community.” He added that South Korea, the United States and their allies must employ “all means” of pressure on North Korea, including not only economic sanctions but also investigations into the North’s human rights abuses. “They are depending on nuclear weapons for their survival, but we must persuade them that there is an alternative and brinkmanship doesn’t work.”

The deal, however, unraveled over differences in nuclear inspections between Washington and the North. And the North has since been making preparations to restart it as well as building a new reactor in Yongbyon, though officials here said the country was still months, if not years, from getting the old, decrepit reactor on line again.