North Korea called Wednesday for direct talks with the United States over a potential missile test, but the Bush administration rejected the overture, saying threats aren't the way to seek dialogue.

"You don't normally engage in conversations by threatening to launch intercontinental ballistic missiles," U.N. Ambassador John Bolton said. "It's not a way to produce a conversation because if you acquiesce in aberrant behavior you simply encourage the repetition of it, which we're obviously not going to do."

President Bush, meeting with European leaders in Austria, said North Korea faced further isolation if it went ahead with any launch.

"It should make people nervous when non-transparent regimes who have announced they have nuclear warheads, fire missiles," Bush said. "This is not the way you conduct business in the world."

Earlier Wednesday, Han Song Ryol, deputy chief of North Korea's mission to the United Nations, said Pyongyang was seeking to resolve the missile test concerns through direct talks with the United States.

"North Korea as a sovereign state has the right to develop, deploy, test fire and export a missile," he told South Korea's Yonhap news agency. "We are aware of the U.S. concerns about our missile test-launch. So our position is that we should resolve the issue through negotiations."

Pyongyang has consistently pressed for direct dialogue with the United States, while Washington insists it will only speak to the North at six-nation nuclear talks. The North has refused to return to the nuclear talks since November, in anger over a U.S. crackdown on the country's alleged illicit financial activity.

State Department deputy spokesman Adam Ereli reiterated the U.S. position Wednesday, saying direct talks with North Korea are "not in the cards."

"The issue of North Korea's nuclear program is not a U.S.-North Korea issue. It is an issue that concerns the entire region," he told reporters in Washington.

"If North Korea wants to talk to the United States about its missile-launch programs or its nuclear program or about security and stability on the peninsula in general, then we should do it through the six-party process," Ereli said. "It's a multilateral approach which provides for, within it, bilateral engagement."

The missile crisis led former South Korean President Kim Dae-jung to cancel a trip next week to the North that could have offered a rare chance for talks. In addition, South Korea said a missile test could affect Seoul's humanitarian aid to Pyongyang.

Washington was weighing responses to a potential test that could include attempting to shoot down the missile, U.S. officials have said.

Bolton said he was continuing discussions with U.N. Security Council members on possible action, and had met with Russia's U.N. ambassador.

"Obviously the priority remains trying to persuade North Korea not to conduct the launch," Bolton said at U.N. headquarters in New York.

After North Korea surprised the world in 1998 by firing a missile that flew over Japan into the Pacific, the Security Council issued a press statement ¡ª its mildest comment. But Bolton said there would be stronger council reaction this time.

"There's no question about it," Bolton said. "We're seeing broad support for something stronger but we don't want to be in a position where we're predicting the future or doing anything other than making it clear we don't think the launch ought to take place."

U.S. Ambassador to Japan Thomas Scheiffer said the United States has means of responding to a North Korean missile test that it didn't have in 1998, and is considering "all options."

In comments published Wednesday, North Korea said its self-imposed moratorium on testing long-range missiles no longer applies because it's not in direct dialogue with Washington, suggesting it would hold off on any launch if Washington agreed to new talks.

North Korea imposed its missile moratorium in 1999 amid friendlier relations with the U.S. during the Clinton administration. During a 2002 summit with Japan, North Korean leader Kim Jong Il signed an agreement to extend the moratorium until at least 2003 ¡ª and reaffirmed the launch ban at another summit in 2004.

Intelligence reports say the North is possibly fueling a Taepodong-2 missile with a range experts estimate could be up to 9,300 miles ¡ª making it capable of reaching parts of the United States.

There are diverging expert opinions on whether fueling would mean a launch was imminent ¡ª due to the highly corrosive nature of the fuel ¡ª or whether the North could wait a month or more.

Victoria Samson, a research analyst with the Washington-based Center for Defense Information, said that if the missile were loaded, it would probably have to be fired "within days."

"That sort of fuel combination ... starts eating away at the missile," she said.

The key question is, however, whether it was indeed loaded or whether the North Koreans just wanted to make it appear that way for the benefit of satellites.

North Korea claims it has nuclear weapons, but isn't believed to have a design that would be small and light enough to top a missile.

South Korean Unification Minister Lee Jong-seok told opposition lawmakers Wednesday a missile test could affect Seoul's humanitarian aid to the North.

"If North Korea test fires a missile, it might have an impact on aid of rice and fertilizer to North Korea," Lee said, according to his spokesman Yang Chang-seok.

South Korea has shipped 150,000 tons of fertilizer this year and had planned to send 200,000 tons more. Pyongyang has asked for 500,000 tons of rice this year, but Seoul has yet to agree.

The European Union appealed Wednesday to the North to cancel any plans for a launch.

"We must say that what they are trying to do ... will have consequences," EU foreign and security affairs chief Javier Solana said on the sidelines of the European meeting with Bush.