BEIJING - China on Tuesday expressed support for dialogue in order to maintain peace and stability on the Korean Peninsula after Pyongyang's announcement that it would cut off all relations with Seoul.

Foreign Ministry spokeswoman Jiang Yu said at a media briefing that both sides' "respective concerns should be resolved through negotiations".

Jiang said that tension on the Korean Peninsula had eased due to the efforts of all related parties since the beginning of this year.

She added that a nuclear-free peninsula and a peaceful Northeast Asia were in the interests of all sides.

A statement issued by the Democratic People's Republic of Korea's (DPRK) National Defense Commission on Monday said it would "never deal with" President Lee Myung-bak of the Republic of Korea (ROK) and his government, accusing Seoul of trumping up false accusations against the DPRK and undermining its reconciliation efforts.

The ROK expressed regret on Tuesday over the DPRK's announcement, urging Pyongyang to be serious about dialogue, Yonhap news agency reported.

ROK Foreign Ministry spokesman Cho Byung-jae said the statement was disappointing.

The statement said the DPRK planned to cut off communications along the countries' eastern border and shut down a liaison office in a joint tourism facility in the country.

"The DPRK will launch a nationwide offensive to put an end to the moves of the Lee group to escalate the confrontation with the DPRK," the statement said.

"As already warned by the DPRK, it will take physical action without any notice any time against any target to cope with the anti-DPRK psychological warfare," it added.

Liu Jiangyong, a professor at Tsinghua University in Beijing, said Lee's tough policy toward the DPRK and the ROK's frequent military drills have been putting pressure on Pyongyang.

"Efforts by the DPRK to resume the Six-Party Talks and further promote denuclearization have been witnessed since the beginning of this year," said Liu. "It would help to ease the tension if Seoul could have a softer policy toward Pyongyang."

Xinhua and AP contributed to this story.