North Korea said the Iraq war proved the need for it to maintain a strong military deterrent against the United States, as the communist nation's withdrawal from the global nuclear arms control treaty officially took effect Thursday.

The North's comments came a day after U.N. Security Council members said they were worried by North Korea's standoff with Washington, but refused to condemn it for pulling out of the Nuclear Nonproliferation Treaty. China and Russia had opposed condemning Pyongyang.

Drawing parallels with the U.S. showdown with Iraq, North Korea said that bowing to demands to abandon its suspected nuclear weapons development would lead to inspections and disarmament, setting the stage for a U.S. invasion.

"The Iraqi war launched by the U.S. pre-emptive attack clearly proves that a war can be prevented and the security of the country and the nation can be ensured only when one has physical deterrent force," said KCNA, the North's state-run news agency. It did not specifically refer to nuclear weapons as a deterrent.

The withdrawal from the nuclear arms control treaty officially took effect Thursday, three months after the North announced it was pulling out. In a similar standoff a decade ago, North Korea announced its withdrawal from the treaty but suspended its decision just before the 90-day notice period lapsed.

Pyongyang and Washington negotiated an energy deal that ended the earlier crisis, though a solution to the current standoff could be more difficult because U.S. officials have taken a harder line this time. They have refused North Korean appeals for direct talks, saying they will not give into blackmail and that other countries must be involved in any solution.

North Korea has said it would ignore any censure by the United Nations, and that economic sanctions -- a measure that the Security Council could eventually consider -- would constitute a declaration of war.

"The U.N. Security Council discussion of the nuclear issue on the Korean Peninsula itself is a prelude to war," said North Korea's Pyongyang Radio. North Korea has issued similar warnings in the past, and belligerence is a trademark of its statements.

The radio, monitored by South Korea's Yonhap news agency, called U.S. efforts to discuss the nuclear dispute at the council "a serious provocation, rupturing efforts for dialogue and spiking tension on the Korean Peninsula."

North Korea has never said that it is developing nuclear weapons, though the United States says it already has one or two atomic bombs. Washington says it has no plans to invade North Korea and seeks a peaceful solution to the nuclear problem, but has not ruled out a military option

Washington wants the problem to be addressed in a multilateral forum including Russia, China, Japan and South Korea.

Russian Defense Minister Sergei Ivanov held talks on the nuclear issue Thursday with South Korean officials in Seoul. Moscow was once a close ally of North Korea, though the friendship faded after the end of the Cold War.

"Solution of the North Korea problem presupposes that Pyongyang returns to all the international non-proliferation regimes and puts its sites under IAEA control, having receiving in return a guarantee of its security, sovereignty and territorial integrity, as well as no attacks," Russia's Interfax news agency quoted Ivanov as saying.

The IAEA is the International Atomic Energy Agency, the U.N. nuclear watchdog.

The standoff flared in October when U.S. officials said North Korea admitted it had a clandestine nuclear program in violation of a 1994 agreement with the United States.

Washington and its allies suspended fuel shipments promised under the 1994 deal, and Pyongyang retaliated by expelling U.N. monitors, taking steps to restart frozen facilities capable of making nuclear bombs and withdrawing from the Nuclear Nonproliferation Treaty.

Reconciliation efforts between the two Koreas have suffered because of the nuclear standoff. Cabinet-level talks between the two sides did not take place as scheduled this week, and other joint projects have been postponed.

On Thursday, North Korea described the South Korean National Assembly as a "group of warmongers," in part because of its decision to approve the dispatch of non-combat troops to support the U.S.-led campaign in Iraq.