North Korea accused the United States of preparing for a nuclear war in the Korean peninsula and said it would bolster its own deterrent in response.

North Korean leader Kim Jong-il applauds as he inspects a sub-unit of the Korean People's Army unit 823, in North Korea, in this undated photograph released by Korea News Service in Tokyo June 29, 2006. [Reuters]

It was the first time North Korea referred so specifically to building up its deterrent -- the usual way of referring to its nuclear programme -- since a crisis began over its suspected plans to test-fire a long-range missile.

A statement carried by the North's official Korean Central News Agency (KCNA) on Saturday condemned as provocative a U.S. decision to deploy an updated version of its U-2 spy plane in South Korea.

It quoted a spokesman for the Committee for the Peaceful Reunification of the Fatherland as saying the United States was driving the situation on the Korean peninsula to the brink of war.

"This grave situation once again goes to prove that peace has been preserved on the peninsula so far entirely thanks to the (Democratic People's Republic of Korea's) DPRK's strong war deterrent.

"Now that the U.S. is set to ignite a nuclear war for the purpose of disturbing peace and stability on the peninsula by force, the DPRK is compelled to bolster up its deterrent for self-defense," he said.

U.S. officials have said North Korea is preparing to test a long-range ballistic missile that some experts say could reach parts of the United States.