North Korea threatened Wednesday to wipe the United States off the map as Washington and its allies watched for signs the regime will launch a series of missiles in the coming days.
Off China's coast, a U.S. destroyer was tailing a North Korean ship suspected of transporting illicit weapons to Myanmar in what could be the first test of U.N. sanctions passed to punish the nation for an underground nuclear test last month.
The Kang Nam left the North Korean port of Nampo a week ago with the USS John S. McCain close behind. The ship, accused of transporting banned goods in the past, is believed bound for Myanmar, according to South Korean and U.S. officials.
The new U.N. Security Council resolution requires member states to seek permission to inspect suspicious cargo. North Korea has said it would consider interception a declaration of war and on Wednesday accused the U.S. of seeking to provoke another Korean War.
"If the U.S. imperialists start another war, the army and people of Korea will ... wipe out the aggressors on the globe once and for all," the official Korean Central News Agency said.
The warning came on the eve of the 59th anniversary of the start of the three-year Korean War, which ended in a truce in 1953, not a peace treaty, leaving the peninsula in state of war.
The U.S. has 28,500 troops in South Korea to protect against an outbreak of hostilities.
Tensions have been high since North Korea launched a long-range rocket in April and then conducted its second underground atomic test on May 25.
Reacting to U.N. condemnation of that test, North Korea walked away from nuclear disarmament talks and warned it would fire a long-range missile.
North Korea has banned ships from the waters off its east coast starting Thursday through July 10 for military exercises, Japan's Coast Guard said.
South Korea's Yonhap news agency reported Wednesday that the North may fire a Scud missile with a range of up to 310 miles (500 kilometers) or a short-range ground-to-ship missile with a range of 100 miles (160 kilometers) during the no-sail period.
A senior South Korean government official said the no-sail ban is believed connected to North Korean plans to fire short- or mid-range missiles. He spoke on condition of anonymity, citing department policy.
U.S. defense and counterproliferation officials in Washington said they also expected the North to launch short- to medium-range missiles. The officials spoke on condition of anonymity to discuss sensitive intelligence.
South Korea will expedite the introduction of high-tech unmanned aerial surveillance systems and "bunker-buster" bombs in response to North Korea's provocations, the Chosun Ilbo newspaper said, citing unidentified ruling party members.
Meanwhile, a flurry of diplomatic efforts were under way to try getting North Korea to return to disarmament talks.
Russia's top nuclear envoy, Alexei Borodavkin, said after meeting with his South Korean counterpart that Moscow is open to other formats for discussion since Pyongyang has pulled out of formal six-nation negotiations.
In Beijing, top U.S. and Chinese defense officials also discussed North Korea. U.S. Defense Undersecretary Michele Flournoy was heading next to Tokyo and Seoul for talks.
South Korea has proposed high-level "consultations" to discuss North Korea with the U.S., Russia, China and Japan.