The United States has warned North Korea to halt what it called provocations and threats, and urged the world to respond to the sinking of a South Korean warship.
The warning was delivered by Secretary of State Hillary Clinton in Seoul, which she is visiting to underline U.S. solidarity with the South amid its confrontation with rival North Korea.
Clinton says the United States stands "rock solid" behind South Korea in the escalating row over the sinking, which was carried out by communist North Korea according to independent investigators.
"The fortunes of our two nations have been bound together for many decades," Clinton told a Seoul press conference today with South Korean Foreign Minister Yu Myung-hwan. "We have stood watchful guard together for 60 years, vigilant in the cause of peace and stability on the Korean Peninsula and in the wider region. And for the United States, the security and sovereignty of South Korea is a solemn responsibility and a rock-solid commitment."
Clinton said the evidence is "overwhelming" that a South Korean naval corvette was sunk by a torpedo from a North Korean submarine on March 26, with the loss of 46 lives. She said the international community has a responsibility and a duty to respond to this "unacceptable provocation."
North Korea denies sinking the "Cheonan" and says it is breaking all ties with the South in protest.
A North Korean news presenter announced the on television that "the Committee for the Peaceful Reunification of Korea formally declares that from now on, it will put into force the resolute measures to totally freeze inter-Korean relations, totally abrogate the agreement on nonaggression between the north and the south, and completely halt inter-Korean cooperation."
At the same time, Pyongyang issued an intemperate statement calling President Lee Myung-bak and his government "confrontation maniacs," "sycophants," and "wicked warmongers."
Clinton arrived in Seoul from China, where she tried to persuade the Beijing leadership to take a stronger line against the North, its close ally.
So far, Beijing has limited itself to mild comments, saying it does not have full information on the "Cheonan" incident and that dialogue is better than confrontation.
Still, Clinton indicated her belief that China will be cooperative in the UN Security Council, to which the South says it will take its case.
"I believe that the Chinese understand the seriousness of this issue and are willing to listen to the concerns expressed by both South Korea and the United States," she said. "We expect to be working with China as we move forward in fashioning a response to this provocation by North Korea."
British-based Korea expert Aidan Foster-Carter tells RFE/RL that -- barring military action -- there are only limited ways open to the international community to punish North Korea for sinking the warship.
"The main option is yet again wearily to take North Korea to the UN Security Council, as the South has already said it will do," Foster-Carter says. "There will be a resolution. I expect China will not oppose it, though I'm not sure they'll support it. But North Korea has been the subject of three such resolutions since 2006 and a chairman's statement."
Foster-Carter says one other thing the United States could do would be to restore the North to the State Department's list of states sponsoring terrorism. North Korea was on that list until removed by the administration of President George W. Bush. But he says that would be a gesture of mainly symbolic value.
Despite Pyongyang saying it is making a complete break with the South, at last reports it had not acted to shut down the Kaesong industrial park, where 120 small and medium size South Korean companies employ 40,000 North Korean workers.
The joint park is a major source of income for the cash-strapped North, and analysts say that as long as it remains open, there is an element of bluff to the North's threats.
However, Pyongyang now says it will block the road to Kaesong if the South goes ahead with its plan to resume broadcasting propaganda through megaphones along the border.
written by Breffni O'Rourke based on agency reports