North Korea says it is cutting off all relations with South Korea after being blamed for sinking a South Korean war ship. The United States said, the decision was not in the best interest of the North Korean people. North Korea's announcement that it is breaking off all ties with the South comes after an independent report showed that the South Korean warship sunk last March was destroyed by a torpedo. South Korea has already broken off most economic ties between the two countries and is pursuing the matter at the United Nations. The American Secretary of State, Hillary Clinton has said, the United States and China will work together to find appropriate and effective response to the Korean crisis.