SEOUL, South Korea - U.S. Secretary of State Hillary Rodham Clinton said yesterday the world must respond to the "unacceptable provocation" represented by the sinking of a South Korean warship blamed on Pyongyang, as the regime shelled out more blistering rhetoric against Seoul and Washington.

Tension on the Korean peninsula has risen dramatically since international investigators said last week that a torpedo fired by a North Korean submarine sank a South Korean warship on March 26, killing 46 sailors.

South Korea, backed by allies, began implementing a package of punitive measures against the North on Tuesday.