After his speech, Pyongyang issued a dispatch threatening that nuclear war could break out on the Korean Peninsula at "any moment," an escalation of the communist North's hostile rhetoric as international pressure grows for it to disarm. 

On the eve of Roh's inauguration Tuesday, North Korea fueled tensions by test-firing a missile into the sea off its east coast. Anticipating a second test, Japanese Deputy Cabinet Secretary Shinzo Abe said Saturday that Pyongyang may fire its long-range Taepodong ballistic missile toward the sea between Japan and the Korean Peninsula, Kyodo news agency reported. 

The North's official news agency also accused Washington of planning massive war games to prepare for an invasion, and said the country is "fully ready to repel the U.S. military attack." 

KCNA - the reclusive Stalinist regime's bulletin board for the outside world - claimed an American RC-135 reconnaissance plane had intruded into North Korean airspace over its east coast almost daily since Feb. 21. 

The U.S. military does not comment on such reports, said Stephen Oertwig, a U.S. military spokesman in Seoul. But North Korea's east coast is dotted with guns and missile bases that U.S. intelligence officials believe can launch ballistic missiles. 

The allegations of intrusions came as the United States and South Korea planned two joint annual military exercises on March 4-April 2 and March 19-26. 

"These unceasing U.S. war drills drive the situation on the Korean Peninsula to such a dangerous pitch of tension that a nuclear war may break out on it any moment," KCNA said Saturday. 

Washington has repeatedly said it has no plans to invade North Korea. 

On Saturday, 100,000 pro-U.S. demonstrators jammed a downtown Seoul plaza to support the presence of 37,000 U.S. troops in South Korea and condemn the North. 

The demonstrators, many of them veterans in military uniforms who waved South Korean and U.S. flags, want the troops to remain to defend the South from a possible Northern attack. 

In addition to the missile test, North Korea has reactivated a 5-megawatt reactor that could produce material for nuclear weapons, U.S. and South Korean officials said earlier this week. 

South Korea sees Pyongyang's recent maneuvers as aimed at forcing the United States into direct dialogue on a nonaggression treaty. 

Washington has refused to hold direct talks unless Pyongyang abandons its nuclear programs and has ruled out a formal nonaggression treaty with Pyongyang, saying it has never signed such a treaty with any country. 

But U.S. officials say they could give the North with a letter guaranteeing its security. They also say the issue should be handled by the U.N. Security Council. 

In his speech, President Roh said he adamantly opposes North Korea's nuclear development, but the issue must be resolved peacefully. 

"If peace on the Korean Peninsula collapses for whatever reason, it would bring about a tremendous calamity that we cannot cope with," Roh said. 

The nuclear dispute flared in October when Washington said North Korean officials had admitted pursuing a nuclear program, which violated a 1994 pact. 

Washington and its allies cut off oil shipments to the impoverished communist state. The North responded by saying it would reactivate its frozen facilities. It also expelled U.N. monitors and withdrew from the global Nuclear Nonproliferation Treaty.