North Korea denounced upcoming joint South Korean and U.S. military drills and said it would "wipe out" the countries with nuclear weapons if they threatened the communist state, its KCNA news agency said on Sunday.
South Korean and U.S. forces on Monday start joint computer simulation and communication drills that come in the wake of rare conciliatory moves by Pyongyang, which this month released two U.S. journalists and a South Korean worker it had held captive.
North Korea regularly denounces joint drills as a preparation for invasion and nuclear war.
"Should the U.S. imperialists and the Lee Myung-bak group threaten the DPRK (North Korea) with nukes, it will retaliate against them with nukes," KCNA quoted a military official as saying. Lee Myung-bak is South Korea's president.
"The U.S. imperialists and the Lee Myung-bak group should clearly understand that it is the iron will and resolute stand of the Korean People's Army to go into action anytime to mercilessly wipe out the aggressors," the official said.
The United States stations about 28,500 troops in South Korea to support the country's 670,000 soldiers. The North's military has about 1.2 million troops but analysts said its ill-equipped army would be no match to superior U.S. and South Korean forces.
The two Koreas are technically still at war because their 1950-53 conflict ended with a cease fire and not a peace treaty.
Impoverished North Korea has been angered by Lee's policy of ending unconditional handouts -- once equal to about 5 percent of the North's estimated $17 billion a year economy -- and instead linking aid to progress Pyongyang makes in ending the security threat it poses to the region.
The North's broken economy has been hit by U.N. sanctions imposed after a long-range rocket launch in April, widely seen as a disguised missile test, and a nuclear test in May.
The sanctions were aimed at cutting off the North's trade in arms, a vital source of hard currency for the cash-starved state.
SANCTIONS ON THE NORTH
Ambassador Philip Goldberg, the U.S. coordinator for implementation of the U.N. resolutions, was expected to travel to Asia this week to strengthen the measures.
Last week, he said efforts to inspect North Korean vessels for illegal weapons and curb financial transactions by Pyongyang entities suspected of proliferation were winning wide backing.
Separately, the chairwoman of the powerful Hyundai Group, one of the few South Korean executives to have direct dealings with North Korean leader Kim Jong-il, has been in Pyongyang for about a week and helped secure the release of the Hyundai worker.
Hyundai Chairwoman Hyun Jeong-eun was scheduled to return to South Korea on Sunday, after extending her visit several times.
She has also been trying to arrange a meeting with Kim to discuss the resumption of tourism at a mountain resort in North Korea run by a Hyundai affiliate that was shut down a year ago after a North Korean soldier shot dead a South Korean tourist who had wandered into a military area.
The resort and factory park run by Hyundai have been vital sources of legitimate foreign currency for North Korea.