Although concerns remain high that North Korea might soon fire a long-range missile, there are some doubts that a launch is imminent. The U.S. ambassador to South Korea warns that a missile launch would only further isolate the communist state.

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South Korean lawmakers say they were told at an intelligence briefing that despite signs Pyongyang is preparing to launch a missile, it is not clear if it will do so.

The politicians say it is not certain North Korea has finished fueling the missile, meaning it could be some days before a launch. In addition, other South Korean experts said cloudy weather over the North recently could delay a launch.

The administration of South Korean President Roh Moo-hyun briefed senior members of his Uri Party on the potential for a North Korean missile launch. Uri spokesman Woo Sang-ho says the administration and party members are of one mind on the prospective launch. He says everyone agrees the situation is very serious, and that North Korea should not launch a missile. A launch, he says, will do no good for anyone.

The United States, Japan, South Korea and other countries have warned North Korea that a launch would not be in its interests. They say Pyongyang should instead return to six-nation talks on ending its nuclear-weapons programs.

U.S. Ambassador to South Korea Alexander Vershbow says a missile test would increase the North's isolation.

"We want to achieve a negotiated solution to the nuclear issue, and we want to establish a more normal relationship with North Korea through the six-party process," he said. "We hope that they do not carry out the test and that they seize the opportunity they have been failing to seize for many months now."

Vershbow says "the door is still open" for dialogue. He also said repeated earlier U.S. statements that a missile launch would require a U.S. response of some kind.

"This missile has a military capability, and we view it therefore as a serious matter," he said.

Vershbow met with former South Korean president Kim Dae-jung, whose 2000 summit meeting with North Korean leader Kim Jong Il brought a thaw in North-South relations. Though Kim Dae-jung is scheduled to make a return visit to North Korea next week, Vershbow says the status of that visit is not clear in light of the possible missile test.

Kim Dae-jung has called for North Korea to return to talks with China, Japan, Russia, South Korea, and the United States aimed at implementing a nuclear disarmament pledge it made last September. He also urges the United States to end sanctions against the North and offer Pyongyang security guarantees.

North Korea last tested a long-range missile in 1998, when a Taepodong missile landed in the Pacific Ocean east of Japan. It then placed a moratorium on long-range missile launches, though it has tested shorter-range weapons. Many experts think Pyongyang is preparing to test another version of the Taepodong.

Pyongyang's official media is criticizing the United States for its development of a missile-defense system. North Korea said that system would lead to a war in space, and accused the U.S. of wanting to attain world supremacy. Pyongyang has often said it needs heavy armament, including nuclear weapons, to protect itself from a possible invasion by the United States.