As the launch window opened Thursday morning, the reclusive, nuclear-armed regime's neighbors were nervously watching for developments from the launch site, which is in a remote area in the northwest of the country.
Japanese missile defense systems scanned the skies above Tokyo and Okinawa. Japan has threatened to shoot down the North Korean rocket if it is seen threatening its territory.
International journalists in Pyongyang were taken on an official visit to a conference that had no connection to the launch. North Korean state television made no mention of the rocket, which the country says is necessary to put a weather satellite in orbit.
North Korea has said that it plans to carry out the launch sometime between Thursday and Monday, between the hours of 7 a.m. and noon (6 p.m.-11 p.m. ET Wednesday-Sunday).
It said Wednesday that fueling of the rocket was under way and would be completed at the "appropriate time."
The announcement last month of the satellite launch -- which countries like the United States and South Korea see as a cover for a ballistic missile test -- ratcheted up tensions in the region and prompted Washington to suspend a recent deal to supply food aid to the North.
International leaders have urged North Korea to cancel the imminent rocket launch, but Pyongyang has refused to back down, insisting that the operation is for peaceful purposes.
''We would like to call (on North Korea) for restraint until the very end," Japanese Prime Minister Yoshihiko Noda said outside his office Thursday, according to the news agency Kyodo.
He added, "We are fully prepared to deal with any contingency," the news agency reported.
South Korea has described the move as a "grave provocation" and says it will respond with "appropriate countermeasures."
The Philippines and South Korea have ordered commercial planes and fishermen to stay clear of the rocket's proposed path during the next few days.
"This launch will give credence to the view that North Korean leaders see improved relations with the outside world as a threat to the existence of their system," U.S. Secretary of State Hillary Clinton said this week. "And recent history strongly suggests that additional provocations may follow."
A recent report from South Korean intelligence officials claimed that North Korea is planning a new nuclear test in the area where it staged previous atomic blasts.
The South Korean intelligence report noted that the two previous rocket launches that Pyongyang said were intended to put satellites into orbit were followed a few weeks or months later by nuclear tests.
The last time Pyongyang carried out what it described as a satellite launch, in April 2009, the U.N. Security Council condemned the action and demanded that it not be repeated.
Also Wednesday, the North Korean ruling Workers' Party held a special conference that helped firm up the position of the secretive state's new leader.
Korean television showed a somber Kim Jong-Un standing beneath two towering statues of his father, Kim Jong Il, and grandfather, Kim Il Sung, while receiving applause from party functionaries and the military.
The meeting of party delegates and the expected launch come as the nation prepares to mark the 100th anniversary of the birth of Kim Il Sung, the founder of North Korea who ruled the Communist state for more than four decades. His birthday on April 15, known as the "Day of the Sun," is a key public holiday in the North Korean calendar.
At the conference, the late former leader Kim Jong Il was given an everlasting title. He is now eternal general secretary of the Workers' Party of North Korea. Current leader Kim Jong Un was named the first secretary of the Workers' Party of North Korea.
The title appears to be a newly created position that sets the stage for a virtual coronation of Kim Jong Un, says North Korea watcher Jonathan Pollack of the Washington-based Brookings Institution.
"Creating this new position is sort of like retiring a jersey number for a famous baseball player," said Pollack. "It shows a deference to his father and to the old guard, while still cementing his control on power."
North Korea announced several other titles for Kim Jong Un, including making him a member of the Political Bureau of the Central Committee and chairman of the Central Military Commission.
Kim Jong Un was already being described as the supreme leader of the party, state and army. But it is still unclear how directly the young Kim, thought to be in his late 20s, is involved in policy decisions.
The leadership transition bears some similarities to the previous transfer of power from one generation of the Kim family to another.
"Kim Jong Il is now venerated at the same level as his father, buried in the same tomb and they are making statues of them riding together on horseback," said Pollack.
"But Kim Jong Un never got the on-the-job training his father did, so he may have this title to allow some mentoring or sharing power and decisions with his elders."