SEOUL - North Korea launched a long-range rocket on Sunday, defying months of pressure from the United States and its allies over what they said was an illegal missile test and jangling nerves across the region.

US President Barack Obama called for a strong international response, with the UN Security Council to hold an emergency meeting Sunday,

while South Korea denounced it as a "reckless" threat to world security.

For several tense minutes, the rocket flew through the airspace of Japan, which had given its military authority to shoot down any threat to its soil - something the North Koreans had warned would be seen as an act of war.

But Japan said the booster rockets fell harmlessly into the water, while the US and Seoul said the launch had failed to get its payload into orbit.

North Korea, which for weeks insisted on its right to the peaceful use of space, said it put a communications satellite into orbit that was broadcasting "immortal revolutionary songs" and anthems praising leader Kim Jong Il.

"The launch vehicle and satellite, developed by our own technology, is a proud fruit of our struggle to bring the nation's space technology to a higher level," the official KCNA news agency said hours after the morning launch.