North Korea says it will enhance its defenses against possible attacks from American nuclear weapons.

Pyongyang's offical Korea Central News Agency accused the United States of scheming to launch a preemptive nuclear attack on it and vowed to take countermeasures.

The KCNA denounced U.S. plans to increase spending for development of mini-nuclear weapons in the coming five years, saying the weapons are mainly targeted at the North.

The KCNA was commenting on plans by the U.S. Department of Energy to increase its spending on development of next-generation mini-nuclear bombs from 6.2 billion dollars this year to 6.6 billion dollars next year and to 7.5 billion dollars in 2009.

The report said the U.S. plans are in violation of the Nuclear Non-proliferation Treaty, a global regime to stem the spread of nuclear technology and weapons.

The report said North Korea has no choice but to intensify its self-defense measures against what it called a U.S. scheme for a preemptive strike.