North Korea has also conducted two nuclear tests since 2006, deepening international concern over its capabilities, although it is not believed to have mastered how to mount a nuclear warhead on a missile.
The U.S., Japan and South Korea last week vowed to seek further U.N. Security Council action if the North conducted a launch. It remained to be seen whether Russia and China, the North's main ally, would agree to further sanctions.
Victor Cha, a Korea expert at Georgetown University and a former White House policy director for Asia, said a successful launch was a major national security concern for the United States.
He said there would still be technical hurdles for the North to overcome, particularly in terms of getting a rocket to re-enter the atmosphere, but it would mean that North Korea is able to launch a long-range ballistic missile — the first rival state to the U.S. do so since the Soviet Union and China.
Rep. Ed Royce, incoming Republican chairman of the House Foreign Affairs Committee, said the launch showed that new North Korean leader Kim Jong Un had no intention of giving up his nuclear weapons program. Royce also criticized U.S. policy toward Pyongyang, calling it a "long-term failure."
"The Obama administration's approach continues to be unimaginative and moribund. We can either take a different approach, or watch as the North Korean threat to the region and the U.S. grows," Royce said in a statement.