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Defiant North Korea fueled up a rocket Wednesday in preparation for what appeared to be an imminent liftoff while the country's young leader strengthened his power with a new title making him the nation's top political official.

Kim Jong Un was named first secretary of the ruling Workers' Party, a new post, while his late father, longtime leader Kim Jong Il, was given the posthumous title of "eternal general secretary" at a special Workers' Party conference, the state-run Korean Central News Agency reported.

Kim Jong Un's formal ascension, nearly four months after the death of his father, comes during a week of events leading up to celebrations Sunday marking the 100th anniversary of the birth of his grandfather, late President Kim Il Sung.

The centennial is a major milestone in the nation Kim Il Sung founded in 1948, and the streets were awash with new posters, banners and the national flag. Outside the city's war museum and the Pyongyang Indoor Stadium, women in traditional Korean dress gathered in clusters, practicing for this week's events.

North Korea has thrown open its doors to dozens of journalists from around the world to report on the events this week designed not only to honor Kim Il Sung but also to demonstrate unity as Kim Jong Un takes power.

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    One of the marquee events is a satellite launch poised to take place as early as Thursday that has raised international concern.

    Space officials call the launch of the Unha-3 rocket, mounted with an Earth observation satellite, a "gift" to Kim Il Sung. They said Wednesday that the final step of injecting fuel into the three-stage rocket was under way in the coastal hamlet of Tongchang-ri.

    "The launch of the Kwangmyongsong-3 satellite is the pride of our nation and of our people," Rim Kwang Myong, a mathematics major at Kim Il Sung University, told The Associated Press.

    A live feed at the General Command Center in the outskirts of Pyongyang showed the rocket on the launch pad covered with a tarp to protect the satellite from the wind.

    Paek Chang Ho, chief of the command center, said the rocket is ready for liftoff as soon as engineers are given the green light. North Korea has informed international aviation, maritime and telecommunications authorities that the launch would take place between Thursday and Monday.

    "We are injecting fuel as we speak," Paek told reporters from a viewing platform in front of a large screen showing the live feed. Sixteen scientists in white lab coats worked at computers below him.

    Because liquid rocket fuel is highly volatile and corrosive, its injection into the rocket is usually one of the final steps in the pre-launch process, experts say. But the weather, and particularly the wind, could force delays.

    The United States, Japan, Britain and others say the launch would constitute a provocation and would violate U.N. Security Council resolutions banning North Korea from developing its nuclear and missile programs.

    Experts say the Unha-3 carrier is similar to the type of rocket that could be used to fire a missile mounted with a nuclear warhead to strike the U.S. or other targets.

    Paek denied Wednesday that the launch was anything but a peaceful civilian bid to send a satellite into space. He said the Kwangmyongsong-3 satellite is designed to send back images and data that will be used for weather forecasts and agricultural surveys.

    "Some parties insist our peaceful space program is a missile test," he told foreign reporters given an exclusive tour of the nation's main satellite command center. "We don't really care what the outside world thinks. This launch is critical to developing our space program and improving our economy."

    U.S. Secretary of State Hillary Rodham Clinton said Tuesday that the launch would be a direct threat to regional security and that the U.S. would pursue "appropriate action" at the Security Council if North Korea goes ahead with it.

    This launch would be the country's third attempt since 1998. Two previous rockets, also named Unha, were mounted with experimental communications satellites and sent from the east coast.

    North Korean officials say the 2009 satellite reached orbit, but the U.S. and other outside observers say they have seen no evidence that it did.

    The new title Kim Jong Un received Wednesday is among several political appointments and promotions expected this week. He was unveiled as father Kim Jong Il's choice as successor at a similar party conference in September 2010.

    Kim Jong Um already has been declared supreme commander of the armed forces, and is expected to gain other new titles formalizing his position as "supreme leader" of North Korea's people and party.

    Delegates also approved a reshuffle of party leadership, electing a new generation of officials to key posts.

    Party member Choe Ryong Hae emerged a rising figure. He was named to the powerful Presidium of the Central Committee's Political Bureau, joining three high-ranking officials already serving on the executive body.

    Choe, who is in his early 60sh and recently was promoted to vice marshal, also was named a vice chairman of the party's Central Military Commission, KCNA said.

    Six others were named to the Political Bureau of the Central Committee, including Jang Song Thaek, who is married to Kim Jong Il's sister, Kim Kyong Hui.

    The immortalization of Kim Jong Il has provided a glimpse into how North Korea will treat the nation's second hereditary succession. After Kim Il Sung died in 1994, he was declared the country's "eternal president," and Kim Jong Il ruled as chairman of the National Defense Commission.

    Kim Jong Un could be promoted to chairman of the National Defense Commission, said Peter Beck, a Korea specialist at the Asia Foundation.

    However, even after his new titles are revealed, much about North Korea's leadership may remain murky, analysts said.

    "North Korea is less monolithic than it looks from the outside, and, particularly as a new top leadership establishes itself in the wake of Kim Jong Il's death, there will be as many questions raised as answers provided by the political choreography," said John Delury, an assistant professor at Yonsei University in Seoul who has made several trips to North Korea in recent years.