North Korea said Tuesday it will restart its graphite-moderated nuclear reactor to extract plutonium for nuclear weapons, breaching its 2007 agreement and inviting international criticism.

The official Korean Central News Agency said the regime would “adjust and change its existing nuclear facilities” in line with its new two-pronged policy of building atomic arms and boosting the economy, citing a spokesman for the General Department of Atomic Energy.

“This applies to uranium enrichment plants and all other facilities at the Yongbyon nuclear complex and includes refurbishing and reactivating the 5-megawatt graphite-moderated reactor that was halted and disabled according to the six-party agreement in October 2007,” it said.

“Ahead of our atomic energy field is the critical task of resolving the country’s strained electricity supply by developing a self-reliant nuclear power industry, and expanding and reinforcing nuclear forces until the world’s denuclearization is realized.”

The announcement came a day after North Korea adopted a statement putting nuclear programs and economic development at the top of the national agenda during a parliamentary session presided over by leader Kim Jong-un.

It will likely spur concern in South Korea and the U.S. following Pyongyang’s daily threats including a warning of nuclear strikes targeting their territories.

Seoul’s Foreign Ministry immediately expressed deep regret of the North’s latest actions.

“North Korea must stick to its previous agreements and promises,” Foreign Ministry spokesperson Cho Tai-young told a news briefing.

Unification Ministry spokesman Kim Hyung-suk said the decision indicates Pyongyang’s attempt to extract plutonium, rescind earlier deals made since the 1990s and undermine the Nuclear Nonproliferation Treaty that it signed in 1985 and walked away from in 2003.

“The situation is serious and worrying. They’re saying the reactor’s reactivation falls in step with the new parallel policy including power generation, but in fact it means an expansion of its nuclear weapons arsenal in terms of mass and quantity,” he told The Korea Herald.

China, the North’s ally and economic sponsor, also expressed regret and urged all six-party members to return to dialogue, saying sanctions cannot “solve the problem fundamentally.”

“China has consistently argued for the realization of denuclearization on the Korean Peninsula, and peace and stability on the Korean Peninsula and in Northeast Asia,” Foreign Ministry spokesman Hong Lei said at a briefing, adding that the current situation is “sensitive and complicated.”

Established in 1986, the reactor had been used to reprocess spent fuel rods to take out plutonium as the fissile material for its atomic weapons and was closed as part of an agreement of the six-nation denuclearization talks in 2007.

The resumption process is expected to take a year including reerecting the cooling tower and recovering reprocessing equipment, another government official said on condition of anonymity due to the sensitivity of the issue.

If fully restored, reprocessing its some 8,000 fuel rods that are used for one year could yield about 7 kilograms of plutonium, sufficient to make at least one fission bomb a year, experts say.

“(North Korea) appears to be trying to play all the cards it has,” the official said.

The regime began installing a 50-megawatt and 200-megawatt reactor in 1984 but their construction was suspended after its 1994 deal with the U.S.

Pyongyang has ratcheted up tension since the U.N. Security Council levied a new round of sanctions to punish its Feb. 12 atomic test, and Seoul and Washington started their annual military drills early this month.

Sunday’s statement called nuclear weapons “the nation’s life” and a core asset of its defense that could not be traded for billions of dollars, citing the U.S. military presence in South Korea as the main reason for its drive to build missiles and nuclear weapons.

The North has also threatened in recent days to shut down the inter-Korean factory complex in Gaeseong, fueling fears among thousands of workers of detention and a possible local armed clash.

Kim last week vowed to retaliate against the U.S.’ dispatch of strategic and stealth bombers to the peninsula, calling it an “ultimatum to wage a nuclear war.”

“The series of North Korea’s threats since its third nuclear test bespeaks that Kim Jong-un’s confidence has exponentially risen,” said Sohn Yong-woo, a professor at Hannam University’s Graduate School of National Defense Strategy in Daejeon.

“There’s a high possibility this year for the immature leader to create an armed conflict in the West Sea to flaunt his credentials at home, strengthen his father’s ‘military-first’ policy and tighten his grip over the military.”

By Shin Hyon-hee (heeshin@heraldcorp.com)