The North's news agency acknowledged the failure. The U.S. said it would carry out its threat to suspend food aid.
FILE - In this April 8, 2012 file photo, a North Korean soldier stands in front of the country's Unha-3 rocket at a launching site in Tongchang-ri, North Korea. North Korea fired the long-range rocket early Friday, South Korean and U.S. officials said, defying international warnings against moving forward with a launch widely seen as a provocation.
SEOUL, SOUTH KOREA - North Korea defied international warnings, launching a rocket Friday that the United States and its allies called a provocative pretext for developing an intercontinental ballistic missile that might one day carry a nuclear warhead. But in what was a major embarrassment to the North and its young new leader, the rocket disintegrated soon after the launch, and U.S. and Japanese officials said its remnants fell harmlessly into the Yellow Sea.
Hours later, the North's state-run Korean Central News Agency acknowledged that a satellite aboard the three-stage rocket had failed to reach orbit. "Scientists, technicians and experts are now looking into the cause of the failure," KCNA said.
The North Korean regime had trumpeted the launch as a showcase of patriotic pride meant to mark the 100th birthday anniversary of the country's founder, the late Kim Il Sung, grandfather of the new leader, Kim Jung Un.
Even though the launch failed, officials from Japan, South Korea and the United States condemned it. U.S. officials said food aid that the Obama administration had planned to send to North Korea would be suspended.
"North Korea is only further isolating itself by engaging in provocative acts and is wasting its money on weapons and propaganda displays while the North Korean people go hungry," White House press secretary Jay Carney said in a statement Thursday night, which was Friday morning in Asia. The United States, Carney said, "remains vigilant in the face of North Korean provocations."
In Japan, government officials said the rocket appeared to fly for more than a minute after it was launched at 7:40 a.m. local time, then broke up at an altitude of 400,000 feet and tumbled in four pieces into international waters west of the Korean Peninsula. In Washington, the Pentagon said the first stage of the rocket fell into the Yellow Sea 103 miles west of Seoul, and the remaining stages "were assessed to have failed and no debris fell on land."
A senior White House official said the failure of the rocket would hurt North Korea's effort to sell weapons to other countries -- somewhat easing the fears of Pyongyang as a nuclear proliferator. It also proved the effectiveness of the heavy sanctions in place on North Korea, this official said, since the measures have deprived the country of access to metals and other technical components necessary for a viable ballistic-missile program.
"Obviously, the rocket launch is pretty embarrassing for Kim Jung Un and North Korea," said Tate Nurkin, a director at Jane's Strategic Advisory Service, in an e-mailed statement. "North Korea is all about ceremony and stature and grand, symbolic gestures."
The rocket, called the Unha-3, blasted off from a launch site near North Korea's western border with China.
U.S. Navy minesweepers and other ships are in the area and expected to begin looking for debris from the rocket, which can offer evidence of what went wrong and what rocket technology North Korea has.
Scott Pace, the director of the Space Policy Institute at George Washington University, said the North will be hard-pressed to get any help in recovering its lost rocket.
Victor Cha, former director for Asia policy on the U.S. National Security Council, said the next step would be to watch whether North Korea conducts a nuclear test, as has been speculated by the South Korean intelligence community. North Korea is reportedly making preparations for such a test soon.
"We have to watch very carefully what they are doing now at the nuclear test site and how they explain this with all those foreign journalists in the country," Cha said.
The Associated Press contributed to this report.