– Los Angeles Times

BEIJING – A defiant North Korea said late Tuesday that 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 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,” Clinton said at the conclusion of two days of talks with Chinese officials.

Clinton flies today to Seoul for meetings 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 convincing 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 potential benefits to the impoverished state of stronger ties to its 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 the South Koreans and the U.S.

“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 water down any U.N. resolution by virtue of its permanent seat on the Security Council and because virtually everything North Korea imports or exports has to cross China’s borders.