In this April 5, 2009 image, a rocket is lifted off from its launch pad in Musudan-ri, North Korea. North Korea announced Friday it plans to launch a long-range rocket mounted with a satellite next month. (AP)

The United States and other countries condemned North Korea on Friday after it announced that it intends to use a rocket to blast a satellite into space, seemingly violating Pyongyang’s recent promise to halt weapons tests in exchange for food.

U.S. officials called the planned launch a “direct violation” of international commitments that could bring to a halt almost every aspect of a deal hammered out two weeks ago that included food aid for the impoverished and isolated country. South Korea’s Foreign Ministry said the rocket test was a “grave provocative act against peace and stability on the Korean Peninsula and in Northeast Asia.”

Although the move follows decades of broken promises by the reclusive North Korean government, it surprised leaders in Washington, Tokyo and Seoul because of the progress in recent weeks after years of stalled talks. The United States was finalizing details for 240,000 metric tons of food North Korea had desperately sought for more than a year.

The deal was also seen as a tentative first step toward better relations with new leader Kim Jong Eun and, possibly, toward a resumption of long-stalled multilateral talks over North Korea’s nuclear program.

North Korea described the launch as both scientific and celebratory, and said it would take place between April 12 and 16 to mark the centennial of founder Kim Il Sung’s birth. The North, which has signed an international space treaty, argues that it has every right to launch satellites for peaceful purposes. In a statement carried by its state-run news agency, the government promised “maximum transparency” and said the launch would encourage the “building of a thriving nation.”

But U.S. and South Korean officials have characterized North Korea’s satellite program as a cover for long-range missile tests, because similar technology is used to launch both. The key difference is a matter of payload: Satellites are designed for communication and observation; missiles are for destruction.

After a similar purported satellite launch in April 2009, the United Nations tightened sanctions against the North, adding a measure to ban Pyongyang from any future launches using “ballistic missile technology.”

U.S. State Department spokeswoman Victoria Nuland said a launch would “pose a threat to regional security and would also be inconsistent with North Korea’s recent undertaking to refrain from long-range missile launches.”

North Korea has refined its ability to launch but has been flummoxed by the sophistication required for the survivability and accuracy of long-distance projectiles. “What they’re trying to do is perfect their reentry heat shield for a ballistic missile,” said Victor Cha, a former White House director of Asian affairs who is now a senior adviser at the Washington-based Center for Strategic and International Studies.

Although the Obama administration has been reluctant to link food aid to negotiations on North Korea’s missile program, North Korean leaders see the two as inexorably connected, U.S. officials say. For that reason, the food deal would probably die if Pyongyang goes ahead with the launch.

A launch “would call into question the credibility of all the commitments that DPRK has made to us,” said Nuland, such as its assurances of adequate monitoring to keep food aid meant for its starving populace from being diverted to its military and elite leaders. Also unclear are terms in the deal that would have allowed international inspectors back into North Korea’s nuclear facilities.

Within hours of the announcement, the U.S. chief negotiator, Glyn Davies, was on the phone with six other countries that have participated in talks with North Korea to discuss how to proceed.

“They have not actually had that launch, so we all need to encourage them to change course,” Nuland said.

According to North Korea’s official statement, the satellite Kwangmyongsong-3 will be launched from a station in the northwestern corner of the country, near the border with China, and directed to the south — unlike a launch three years ago that traveled over northern Japan.

“A safe flight orbit has been chosen so that carrier rocket debris to be generated during the flight would not have any impact on neighboring countries,” the North’s news agency said.

Previous North Korean launches have been more successful in sparking international ire than in showing off indigenous technology. The North said its previous long-range rocket launch, on April 5, 2009, placed into orbit a satellite that broadcast patriotic songs. But outside analysts say the launch ended in failure, with no object of any kind entering orbit.

Angry about global condemnation of that launch, North Korea expelled international nuclear inspectors from the country and walked out of the six-party talks on its weapons program.

One month later, North Korea conducted its second nuclear test.

Analysts said that participants in the six-party talks — which include the United States, South Korea, Russia, China and Japan — could see a similar breakdown in relations this time around.

“I’m pretty sure the Chinese are upset over this. They worked fairly hard in the recent months to obtain the food-for-nukes deal, only for this to happen,” said Christopher R. Hill, former U.S. negotiator in the six-party talks and assistant secretary of state for Asia during the George W. Bush administration.

South Korea is to host the Nuclear Security Summit this month, which will bring together some 50 world leaders, including President Obama.

The North’s announcement on Friday, some analysts in Seoul said, felt more like evidence of a divide within Pyongyang’s leadership since the death of Kim’s father, Kim Jong Il, rather than a well-orchestrated strategy to gain leverage.

“It suggests there’s not quite the unity of command, that the people doing the negotiating on food aid are not the same as those in charge of the missile launches,” Hill said.

For years, the North has promised its people a nationwide celebration in mid-April this year, pledging to become a “strong and prosperous” nation with something akin to first-world status. A satellite or missile test at that time, some experts said, could be sold domestically as evidence of North Korea’s strength.

“For now, it is unclear what is behind this decision,” said Ryoo Kihl-jae, at Seoul’s Institute for Far Eastern Studies. “But even if North Korea is to go on launching its missile or satellite, there aren’t any more measures for the international community to take. . . . All possible sanctions have already been imposed.”

As recently as last week, North Korean officials were expressing a desire to rebuild the country’s relationship with the United States. Now U.S. officials are scrambling to figure out how to respond.

“The main option now,” Cha said, “is probably to go to the U.N. Security Council and argue that this is a violation of security resolutions on North Korea. But you may see resistance from China and possibly Russia on that.”

Wan reported from Washington. Special correspondent Yoonjung Seo in Seoul contributed to this report.