U.S. officials reacted quickly and sharply to the launch. In language they had used for weeks while the North set a timetable, they said it was "provocative" and a threat to stability in an already tense region that includes Japan and South Korea, two of America's staunchest Asian allies.

The U.N. Security Council planned to meet in emergency session at Japan's request late Sunday. Obama, traveling in Europe, called for international consensus to condemn the launch of what the North claimed was a satellite. The U.S. and others say it violates a U.N. ban on ballistic missile activity by the communist state even though the satellite failed to reach orbit.

"North Korea broke the rules once again by testing a rocket that could be used for long range missiles," Obama said in a speech on nuclear proliferation in the Czech Republic.