The US has led international condemnation of the successful launch of North Korea's first space satellite.
In Pyongyang, North Koreans danced in the streets to celebrate the rocket launch, while in Washington, Seoul and Tokyo, leaders pushed for consequences.
The event is widely seen as a test that takes the country one step closer to being capable of launching nuclear bombs over the Pacific.
The launch of a three-stage rocket - similar in design to a model capable of carrying a nuclear-tipped warhead as far as California - raises the stakes in the international stand-off over North Korea's expanding atomic arsenal.
As Pyongyang refines its technology, its next step may be conducting its third nuclear test, experts warn.
The UN Security Council, which has punished North Korea repeatedly for developing its nuclear programme, was to meet behind closed doors today.
The White House called the launch a "highly provocative act that threatens regional security," while even the North's most important ally, China, expressed regret.
In Pyongyang, however, pride over the scientific advancement outweighed the fear of greater international isolation and punishment. North Korea, though struggling to feed its people, is now one of the few countries to have successfully launched a working satellite into space from its own soil; its rival South Korea is not on the list, though it has tried.
Today's launch was North Korea's fourth bid since 1998. An April launch failed in the first of three stages, raising doubts among outside observers whether North Korea could fix what was wrong in just eight months - although those doubts were erased today.
The Unha rocket, named after the Korean word for "galaxy", blasted off from the Sohae launch pad in Tongchang-ri, northwest of Pyongyang, just three days after North Korea indicated that technical problems might delay the launch.
In an indication that North Korea's leadership was worried about the success of the launch, the plan was kept quiet inside North Korea until a special noon broadcast on state TV declared the launch a success.
At one hotel bar today, North Koreans watched raptly, cheering and applauding at the close of the brief broadcast. As vans mounted with loudspeakers drove around the capital announcing the news, North Koreans bundled up in parkas ran outside to celebrate.
Director Kim Hye Jin said the satellite was broadcasting "Song of Gen Kim Il Sung" and "Song of Gen Kim Jong Il" in space. He reiterated North Korea's intention to keep launching satellites in the future.
Space officials say the rocket is meant to send a satellite into orbit to study crops and weather patterns.
But the launch could leave Pyongyang even more isolated and cut off from much-needed aid and trade.
The UN imposed two rounds of sanctions following nuclear tests in 2006 and 2009 and ordered the North not to conduct any launches using ballistic missile technology. Pyongyang maintains its right to develop a civilian space programme, saying the satellite will send back crucial scientific data.
The White House condemned what National Security Council spokesman Tommy Vietor called "yet another example of North Korea's pattern of irresponsible behaviour".
He said: "The United States remains vigilant in the face of North Korean provocations and fully committed to the security of our allies in the region.
"Given this current threat to regional security, the United States will strengthen and increase our close coordination with allies and partners."
Mr Vietor said the international community must "send a clear message that its violations of UN Security Council resolutions have consequences".
For North Koreans, Wednesday's launch caps a heady year of milestones: the centenary of the birth of Kim Il Sung, the nation's founder, and the inaugural year of leadership under his grandson, Kim Jong Un. And on December 17, North Korea will mark the anniversary of the death of leader Kim Jong Il.
"How happy would our General (Kim Jong Il) have been," Pyongyang resident Rim Un Hui said.
"I'm confident that our country will be stronger and more prosperous under the leadership of Kim Jong Un."