North Korea says it will not attend six-party nuclear talks for an indefinite period.

A spokesman for the North& 039 s Foreign Ministry said Thursday North Korea cannot participate in the multilateral talks unless the United States drops its hostile policy toward the communist country.

North Korea also said publicly for the first time that it had built nuclear weapons for self-defense.

In a statement carried by the North& 039 s official news agency KCNA, North Korea said it had wanted the six-party talks but was compelled to suspend its participation for an indefinite period.

The statement added that Pyongyang would take measures to bolster its nuclear weapons arsenal in order to protect its ideology, system, freedom and democracy. However, it did not elaborate on what those measures might be.

The statement went on to says that the second-term Bush administration& 039 s intention to antagonize the north and isolate and stifle it at any cost has become clear, citing President Bush& 039 s inaugural address and his State of Union speech.

The KCNA also criticized U.S. Secretary of State Condoleezza Rice& 039 s description of the North as an "outpost of tyranny."

The nuclear standoff began in October 2002, when the United States accused North Korea of operating an illegal uranium program. Since then, the two countries have held three rounds of talks, together with China, Japan, Russia and South Korea, but little progress has been made.

A fourth-round meeting was scheduled to be held before the end of September last year, but North Korea boycotted it, citing Washington& 039 s hostile policy.