North Korea has announced it does possess nuclear weapons. It made a similar claim last year, but later retracted it.  In an official statement Thursday, Pyongyang also said it is suspending participation in six-party talks on its nuclear ambitions, accusing the United States of conducting a "hostile policy" toward the Communist state. 

U.N. Secretary-General Kofi Annan urged North Korea to resume multinational talks, and asked the other five nations engaged in those talks to entice Pyongyang back to the table.

In a statement read by North Korea's official news agency, the government said its nuclear arms were for "self-defense" purposes against what it called the Bush administration's "undisguised policy to isolate and stifle" Pyongyang.

The statement cited a recent remark by U.S. Secretary of State Condoleezza Rice, calling North Korea an "outpost of tyranny," as its justification for refusing to rejoin any future talks.

Speaking in Luxembourg, where she wrapped up a nine-nation European trip, Secretary Rice said North Korea is only deepening its isolation from the rest of the international community. She also dismissed accusations that Washington is taking an aggressive stance toward Pyongyang.

"The North Koreans have been told by the President of the United States himself that the United States has no intention to attack or invade North Korea, the North Koreans have been told that they can have security assurances on a multilateral basis,” said Secretary Rice. “Those security assurances will of course, include the United States if they are prepared to take a definitive decision   to dismantle their nuclear weapons programs, and to do so in a way that is verifiable."

A South Korean foreign ministry spokesman said Seoul is "deeply concerned" about the announcement, adding that Seoul believes the North has enough materials to produce one or two nuclear weapons.

Pyongyang expelled the last UN nuclear monitors in late 2002 and has never tested a nuclear bomb.  International officials have long suspected the North had one or two nuclear bombs, and enough fuel for several more.

Since 2003, the U.S., the two Koreas, Japan and Russia have held three rounds of talks in Beijing aimed at persuading the North to abandon nuclear weapons development in return for economic and diplomatic incentives.

A fourth round, scheduled for last September, was cancelled when the North refused to attend, citing what it called a hostile U.S. policy.