Any nuclear tests by North Korea would be an unacceptable threat to peace and peace and must not be carried out, the Bush administration said Tuesday. State Department spokesman Sean McCormack said the United States will work with its allies to discourage such a reckless action, and suggested that any test would further isolate Pyongyang from the rest of the world. McCormack and other State Department officials made statements throughout the day warning that a nuclear test would effectively deny North Koreans possible benefits they might reap by returning to negotiations about their nuclear program. Bush administration officials were reacting to a North Korean declaration that came Tuesday, as Pyongyang said it would conduct a nuclear test in the face of what it claimed was the U.S. extreme threat of a nuclear war. North Korea has not previously conducted any known nuclear tests, although the communist country claims to have nuclear weapons. The U.S. and its allies have tried to bring North Korea back into negotiations to abolish the country s nuclear weapons program. Pyongyang abandoned the talks because of U.S. financial restrictions imposed for its alleged illegal activity, including money laundering and counterfeiting. Most recently, the so-called rogue state alarmed the world when it test-fired seven missiles in July, including one believed to be capable of reaching the United States.