BEIJING — A defiant North Korea said late Tuesday it would sever all ties with South Korea, cut off communications and expel workers from a jointly run industrial park in a bellicose response to the South's efforts to seek redress for the sinking of one of its ships.
Although South Korea has said it will not retaliate with force, instead seeking sanctions before the U.N. Security Council, Pyongyang earlier in the day accused Seoul of making a "deliberate provocation aimed to spark off another military conflict."
In Beijing, Secretary of State Hillary Rodham Clinton said the United States stood firmly behind South Korea and urged China to join in condemning North Korea's behavior, as Beijing did last year when the North tested a nuclear weapon.
"We expect to be working together with China in responding to North Korea's provocative action, and promoting stability in the region," said Clinton at the conclusion of two days of talks with Chinese officials that were supposed to concentrate on economics but ended up being overshadowed by the Korean crisis.
Clinton flies today to Seoul to meet with Japanese and South Korean officials. Chinese Premier Wen Jiabao is also headed to Seoul to meet Friday with South Korean President Lee Myung Bak.
After Clinton's meetings with the Chinese, U.S. officials could claim no progress in persuading Beijing to support U.N. deliberations on North Korea's alleged attack, but said talks would at least continue.
Philip J. Crowley, the chief State Department spokesman, said North Korea's decision to sever ties with the South was "odd," given the benefits to the impoverished state of stronger ties to their wealthier neighbor.
The South Korean naval vessel Cheonan was on patrol in the Yellow Sea on March 26 when an explosion ripped apart the hull, killing 46 crew members. Investigators last week declared what was already widely believed in South Korea: that the sinking was the result of an attack by a North Korean torpedo.
The Chinese already have signaled their reluctance to punish North Korea, infuriating South Koreans and Americans.
"It is disgusting the way the Chinese just sit on their hands and do nothing. This backward and clumsy behavior is not fitting their supposed place as the predominant power in Asia," said Victor Cha, a former National Security Council Asia director now at a Washington think tank, the Center for Strategic and International Studies.
China's cooperation is important because it can block or weaken any U.N. resolution by virtue of its permanent seat on the Security Council and because virtually everything North Korea imports or exports must cross China.
North Korea shows no signs of flinching in what is increasingly a battle of nerves.
Pyongyang issued a flurry of threats during the day. It accused South Korea of dispatching "dozens" of warships across the maritime border and said it would "put into force practical military measures to defend its waters."
North Korea said it had given permission for its soldiers to shoot at South Korean loudspeakers — a response to an announcement Monday that Seoul would resume broadcasting propaganda across the 150-mile-wide demilitarized zone.
The strongest measure was the severing of all relations and communications with South Korea.
However, spokeswoman Lee Jong Joo said that although the North was expelling eight South Korean officials from a joint industrial complex in Kaesong, some 800 South Korean company managers and workers will remain. Yonhap news agency said that suggested the North had no intention of completely shutting down the Kaesong park, as South Korea also decided to keep the complex intact.
More than half a century after the 1950-53 Korean War, there is still no telephone or postal service between the countries.
The United States and South Korea are planning major military exercises off the Korean peninsula in a display of force. The United States has 28,500 troops in South Korea.
The threats looked like a tried-and-true North Korean maneuver — escalating the tensions in order to remind South Korea how vulnerable its economy is to any hint of renewed conflict.
It's possible that North Korean leader Kim Jong Il might be able to exploit rising tensions with South Korea to distract his nation's citizens from the abysmal state of their economy. The ailing 68-year-old leader is also in the process of trying to install his youngest son, who is in his 20s, as his successor.
"Dictatorships undergoing internal political turmoil generally manifest belligerent external behavior," said the Washington-based Center for Strategic and International Studies in a report released Tuesday.