North Korea threatens South, restarts plutonium plant

By Jon Herskovitz

SEOUL (Reuters) - North Korea, facing international censure for this week's nuclear test, threatened on Wednesday to attack the South after it joined a U.S.-led plan to check vessels suspected of carrying equipment for weapons of mass destruction.

Adding to tensions in the region, South Korean media reported that Pyongyang had restarted a plant that makes plutonium that can be used in nuclear bombs.

In Moscow, news agencies quoted an official as saying that Russia is taking precautionary security measures because it fears mounting tensions over the test could escalate to war.

Russia also called the North Korean ambassador to the foreign ministry and told him Moscow has "serious concern" over this week's test, the ministry said.

U.S. Secretary of State Hillary Clinton reaffirmed U.S. commitments to allies Japan and South Korea, said North Korea was behaving in a "provocative and belligerent manner" toward its neighbors, and that there were consequences to such behavior.

Both Moscow and Washington said they hoped North Korea would return to the six-party talks aimed at ending its nuclear program.

North Korea's latest threat came after Seoul announced, following the North's nuclear test on Monday, it was joining the U.S.-led Proliferation Security Initiative, launched under former U.S. President George W. Bush's administration.

'POWERFUL MILITARY STRIKE'

"Any hostile act against our peaceful vessels including search and seizure will be considered an unpardonable infringement on our sovereignty and we will immediately respond with a powerful military strike," a North Korean army spokesman was quoted as saying by the official KCNA news agency.

He reiterated that North Korea no longer was bound by an armistice signed at the end of the 1950-53 Korean War because Washington had ignored its responsibility as a signatory by drawing Seoul into the anti-proliferation effort.

The U.N. Security Council is discussing ways to punish Pyongyang for Monday's test, widely denounced as a major threat to regional stability and which brings the reclusive North closer to having a reliable nuclear bomb.

Diplomats in New York said that the five permanent council members -- the United States, Britain, France, China and Russia -- and Japan agreed at a meeting on Tuesday to beef up and expand existing U.N. sanctions against Pyongyang. South Korea, which is not a council member, was also present.

"There is a clear commitment by the (seven countries) to go for sanctions," a U.N. diplomat close to the talks but who declined to be identified said on Wednesday. "There was no reluctance that I could notice from either China or Russia."

Diplomats said the seven countries would not have a draft sanctions resolution ready to circulate to the full 15-nation council before next week at the earliest.

One diplomat said possible steps include a ban on importing and exporting all arms and not just heavy weapons, asset freezes and travel bans for North Korean officials, placing more firms on a U.N. blacklist and adding goods to it. The diplomats said cargo inspections were also possible, though China is reluctant.