North Korea accused the United States on Saturday of provoking war by carrying out an anti-missile test over the Pacific and holding military drills with South Korean forces on the divided peninsula.
The US military shot down a dummy warhead over the Pacific on Friday in what it called a "huge step" in the development of an anti-missile shield activated in July to guard against missiles test-fired by North Korea.
The North's Committee for Peaceful Reunification of the Fatherland said the joint exercise was the most provocative yet and, given its scale and content, a virtual declaration of war against the communist state.
"On the occasion of the Ulchi Focus Lens joint military drills, the United States even conducted a missile test aimed at attacking us from the South and the US homeland and intercepting our missiles," said the committee's statement, carried by the official KCNA news agency. On Friday, US and South Korean troops ended the 12-day exercise designed to test command structures and communications.
Ulchi Focus Lens has been staged annually without incident since 1975, but the North usually denounces the drills as a prelude to invasion and nuclear war.
This year's exercise took place with tensions high on the peninsula after North Korea test-fired a barrage of missiles on July 5 and after reports in August that it might be preparing to test a nuclear weapon.
Pyongyang said last year that it now possessed nuclear arms, which it described as a self-defence deterrent. There has been no outside confirmation of this development.
Since late 2005, the reclusive state has boycotted six-country talks aimed at coaxing it into scrapping its atomic programmes, blaming this on a US crackdown on its overseas financial dealings.
"The United States are wielding the bat of power and trying to get someone to surrender to them ... it will cement the determination of our armed force and people to build up self-defence deterrent," Saturday's statement said.