North Korea maintains that it is launching an observation satellite, but other countries think this is a cover for a missile test.
Ryu Kum Chol, deputy director of the Space Development Department of the Korean Committee for Space Technology, dismissed assertions that the launch is a cover for developing missile technology, calling the accusations "nonsense."
"No country in the world would want to launch a ballistic missile from such an open site," he said.
The U.S. says the launch will jeopardize an agreement where Washington provides food aid in exchange for a freeze on nuclear activity, including a moratorium on long-range missile tests.
Meanwhile, Workers' Party delegates are scheduled to convene Wednesday for the fourth conference of North Korea's ruling political party, where new leader Kim Jong Un is expected to inherit titles once held by his father, the late Kim Jong Il.
The Associated Press contributed to this report.