South Korean soldiers patrol the demilitarized zone separating North… (Jeon Heon-Kyun / European…)
SEOUL — Escalating the stakes of a standoff with Washington and its allies, North Korea is signaling that it will abandon two decades of negotiations to constrain its nuclear program and will close the door on any deal over its atomic weapons and production facilities.
The regime said Tuesday that it would expand all parts of its nuclear arsenal, including reactivating a plutonium-producing reactor complex at Yongbyon shut in 2007 as part of a disarmament agreement. Although restarting the Soviet-era facilities could take more than six months, the announcement sparked concern among world leaders that a miscalculation could lead to military confrontation.
North Korea also said it would bolster its "nuclear armed forces in both quantity and in quality." The statement came two days after its untested young leader, Kim Jong Un, described North Korea's nuclear weapons program as a "treasure" that would not be abandoned or traded "for billions of dollars."
United Nations Secretary-General Ban Ki-moon, a former South Korean foreign minister, said he was "deeply troubled" that the crisis has "gone too far." He called for urgent talks with North Korea.
"Things must begin to calm down," Ban said. "There is no need for the DPRK [North Korea] to be on a collision course with the international community. Nuclear threats are not a game."
U.S. Secretary of State John F. Kerry, after meeting South Korea's foreign minister at the State Department, said it would be a "provocative act" for the North to restart its reactor, which produces spent material that can be reprocessed into nuclear bomb fuel.
"The bottom line is very simply that what Kim Jong Un has been choosing to do is provocative, it is dangerous, reckless, and the United States will not accept the DPRK as a nuclear state," he said.
Kerry will visit Tokyo, Seoul and Beijing next week in a trip aimed at persuading China to sharpen pressure on its neighbor and ally, officials say.
A Chinese foreign ministry spokesman, Hong Lei, said Beijing regretted North Korea's latest move and called for restraint on all sides.
Increasingly bellicose threats by the regime in Pyongyang since it conducted its third and most powerful underground nuclear test in February have increased tension in Northeast Asia to the highest level in years.
Tuesday's announcement about the reactor heightened the potential danger by suggesting that North Korea intends to expand its nuclear arsenal and make its infrastructure permanent. "We will act on this without delay," a spokesman for the North Korean General Department of Atomic Energy said.
Although brinkmanship and bluster are hallmarks of Pyongyang's negotiating strategy, disarmament experts and regional observers are more worried now because of the relative inexperience of North Korea's leader, who took over after the death of his father, Kim Jong Il, in December 2011.
"Kim Jong II, for all his faults, turned out to be very savvy about just how far he could go," said Scott Snyder, a Korea specialist at the nonpartisan Council on Foreign Relations in Washington. "I'm not sure Kim Jong Un has that sense. He is on the verge of becoming Public Enemy No. 1, and that could be a fatal mistake."
Shi Yinhong, a professor of international relations at People's University in Beijing, warned that "this is one of the most dangerous moments since 1953," when hostilities in the Korean War ended.
"For decades, they've always suggested they were open to the possibilities that the nuclear facilities could be traded away," said Jon Wolfsthal, a former Obama administration official now at the Monterey Institute for International Studies. "Now they're saying, 'These are the crown jewels, and they're not going away.'"
Wolfsthal predicted that the White House would not make diplomatic concessions or shift policy in response to the threats. But if Pyongyang starts moving troops or weapons to directly threaten U.S. bases or allies, or begins selling nuclear weapons or technology to Iran or other potential adversaries, that will change. If the nuclear program "begins to metastasize, all bets are off," he said.
North Korea has insisted that it is acting in self-defense. It has accused Washington of using annual military exercises with South Korean forces as a pretext for war, and it has been angered by the additional sanctions imposed by the U.N. after it carried out its last nuclear test.
In response to the sanctions, North Korea has vowed to attack the United States and its military bases, canceled the 1953 armistice that ended the Korean War and closed telephone hotlines with South Korea that had been set up to reduce the risk of military misjudgment.