Tensions are rising on the Korean peninsula after the United States voiced its "unequivocal" support for South Korea following Seoul’s allegations that North Korea torpedoed and sank a South Korean warship in March, killing 46 sailors.
In a statement, the White House said President Barack Obama had directed military commanders to "coordinate closely" with their South Korean counterparts to "deter future aggression." The United States keeps 28,000 troops on the peninsula.
On a visit to Beijing, U.S. Secretary of State Hillary Clinton urged China, North Korea's closest trading partner and only major ally, to cooperate with Washington.
"North Korea is also a matter of urgent concern,” Clinton said. “Last year, we worked together to pass and enforce a strong UN Security Council resolution in the wake of North Korea's nuclear test. And today, we face another serious challenge provoked by the sinking of the South Korean ship. So we must work together again to address this challenge and advance our shared objectives for peace and stability on the Korean peninsula."
China has been reluctant to back tough measures against communist North Korea, including over Pyongyang's nuclear program, which has been cause for serious worry in the West. North Korea says it has the right to expand its nuclear deterrent and that it has developed nuclear arms in a transparent manner.
South Korea's President Lee Myung-bak said Seoul would refer North Korea to the UN Security Council in response to the sinking of the "Cheonan" corvette, one of the deadliest incidents between the two countries since the 1950-1953 Korean War. The two sides have never signed a formal treaty ending the hostilities.
In a strongly worded televised address, Lee demanded an apology and said those who carried out the attack must be punished. He added that North Korean ships would no longer be allowed to use South Korean-controlled waters.
"From now on, the Republic of Korea will not tolerate any provocative act by the North and will maintain the principle of proactive deterrence,” Lee said. “If our territorial waters, airspace, or territory is violated, we will immediately exercise our right of self-defense."
Lee said South Korea had suspended “inter-Korean trade or other cooperative activity,” calling them “meaningless” under current circumstances.
But South Korean Unification Minister Hyun In-taek said Seoul would maintain a joint economic project in the North Korean city of Kaeson.
"The establishment of new businesses in the Kaesong Industrial Complex as well as additional investment in the joint economic district will be prohibited,” Hyun said. “The current production activities in the complex will not be discouraged, but the number of South Korean personnel in the district will be reduced."
The White House said South Korea's actions are "called for and entirely appropriate."
South Korea's Defense Minister Kim Tae-young also announced antisubmarine naval exercises will be conducted jointly with U.S. forces.
"We are planning on holding a South Korea-U.S. combined antisubmarine exercise in the West Sea in the near future,” Kim said. “Elite forces from the Republic of Korea and the United States will participate in this training exercise, which will serve as an opportunity to focus on the enhancement of defensive tactics against underwater attacks by North Korea and our surface-firing capabilities."
The measures come less than a week after experts from the United States, Britain, Australia, and Sweden said in a report that a torpedo had hit the "Cheonan." They reported that parts of the torpedo retrieved from the sea floor had lettering that matched a North Korean design.
North Korea has denied involvement in the sinking, calling the investigation results a "fabrication."
Seoul said it would resume cross-border broadcasts into North Korea over loudspeakers. The North Korean military today warned against such “new tools for psychological warfare," saying it would fire on South Korean loudspeakers.
The official KCNA news agency quoted a North Korean military commander as saying that if South Korea responds to such actions, "more powerful physical strikes will be taken to eradicate the root of provocation."
with agency reports