<p><br /> US Secretary of State Hillary Clinton has arrived in Seoul to discuss North Korea.<br /> </p><p><br /> Pyongyang announced on Tuesday it was severing all ties with the South and threatened its wealthy neighbour with military action if it continued to violate its waters off the west coast.<br /> </p><p><br /> The comments mark a new high in tensions on the divided peninsula which follow the sinking of a South Korea warship in March which Seoul blames on the North.<br /> </p><p><br /> The torpedoing the Cheonan corvette killed 46 sailors.<br /> </p><p><br /> North and South Korea are still technically at war, since the Korean War ended in a truce without a peace treaty.<br /> </p><p><br /> Clinton is meeting with South Korean President Lee Myung-bak and Foreign Minister Yu Myung-hwan to discuss North Korean matters, including the ship's sinking, the communist county's threats to sever all ties with the South, and possible military action.<br /> </p><p><br /> Both the United States and South Korea blame North Korea for the sinking of the Cheonan.<br /> </p><p><br /> Clinton said on Tuesday in Beijing that the United States would work with China to come up with an effective and an appropriate response.<br /> </p><p><br /> The United States, which has 28,000 troops on the peninsula, has thrown its full support behind South Korea and says it is working to stop tensions from escalating.<br /> </p>
