The United States sternly warned North Korea on Monday night not to test-fire a long-range missile thought powerful enough to reach the US coast, as officials suggested economic sanctions could be imposed as punishment. Japan, Australia and New Zealand also cautioned the impoverished country that a missile test would bring serious consequences and further isolate the regime, while South Korea asked the North not to put its neighbor in danger with such a launch. "The government explained to North Korea the serious repercussions a missile launch would bring and strongly demanded that test fire plans be scrapped," South Korea's Uri Party spokesman Woo Sang-ho said in a statement after politicians were briefed by officials including Unification Minister Lee Jong-seok. "The party and the government reached an understanding that the current situation is very grave, that the North should not fire a missile and that the worsening of the situation to be caused by a North Korean missile launch is not beneficial to anybody," Woo said. North Korea on Wednesday made its first public reference to its missile program since it apparently began preparations for a test launch, while a US official in Washington confirmed tha the North has completed fueling a ballistic missile that is poised to fire. US intelligence indicates that the long-range missile, believed to be a Taepodong-2, is fully fueled, the US official said, requesting anonymity because the information comes from sensitive intelligence methods. That reportedly gives the North a launch window of as much as a month for the missile, its most advanced model that experts say could reach parts of the US "It would be a very serious matter and, indeed, a provocative act should North Korea decide to launch that missile," US Secretary of State Condoleezza Rice said in Washington. At UN headquarters in New York, US Ambassador John Bolton said he was holding preliminary consultations with Security Council members on possible action if North Korea fires the missile. The US ambassador to Japan, Thomas Schieffer, said economic sanctions were an option. "I think sanctions would have to be considered, but I wouldn't want to describe what actions we might take," Schieffer said through a US Embassy official. Meanwhile, the North mentioned its missile program on its state-controlled evening TV news for the first time during the latest crisis, while not saying whether it intended a launch. The report, citing a Russian commentary, said the North "has the due right to have a missile that can immediately halt the United States' reckless aerial espionage activity." The North has repeatedly complained in recent weeks about alleged US spy planes watching its activities. Some North Korean reports put the claimed espionage in the area where foreign officials say preparations for a long-range missile launch are continuing. 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. The North has boycotted international nuclear talks since last November, in anger over US financial restrictions against a Macau bank and North Korean companies for alleged illicit activities. North Korea test-fired a Taepodong-1 missile over northern Japan in 1998, but claimed that it was a satellite launch. It has abided by a self-imposed moratorium on long-range missile tests since 1999 Japan's Mainichi newspaper reported Monday that after fueling is finished, the missile has a launch window of about one month, citing unidentified officials in Washington familiar with US and North Korean matters. Japanese Prime Minister Junichiro Koizumi said on Monday that Japan would react sternly to a missile launch by North Korea. Australia and New Zealand made similar comments. In Seoul, South Korea's ruling party called on North Korea not to put its "friend in danger" by testing the missile, while the opposition accused the government of not leaning hard enough on the North to stop the launch.