The United States and its allies rushed to condemn North Korea's failed rocket launch as a "provocative act" that threatened regional security, while Pyongyang's main ally China urged calm.
The US lashed out at "propaganda displays", saying Friday's launch breached Pyongyang's commitments and harmed Asian security.
"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 spokesman Jay Carney said.
"Despite the failure of its attempted missile launch, North Korea's provocative action threatens regional security, violates international law and contravenes its own recent commitments."
Washington's key regional allies, Seoul and Tokyo, spoke in unison, blasting the launch as contrary to United Nations resolutions.
"North Korea's launch ... is a clear breach of the UN resolution that prohibits any launch using ballistic missile technology. It is a provocative act threatening peace and security on the Korean peninsula and Northeast Asia," South Korean Foreign Minister Kim Sung-hwan said.
Tokyo, which had vowed to intercept any rocket that appeared to threaten its territory, agreed the launch was likely to have been a missile, not the satellite-carrying rocket Pyongyang had claimed it to be.
"Even if it was a failure, it is a grave provocation to our country and other countries concerned and violates UN Security Council resolutions," Chief Cabinet Secretary Osamu Fujimura said.
UN chief Ban Ki-moon called the rocket launch "deplorable" and a threat to regional stability.
"Despite its failure, the launch of a so-called 'application satellite' by the Democratic People's Republic of Korea is deplorable as it defies the firm and unanimous stance of the international community," Ban's spokesman said in a statement.
North Korea's sole patron, China, took six hours to respond to the launch and remained very neutral when it did finally speak.
"We hope all relevant parties can maintain calm and restraint, and refrain from acts that would harm peace and stability on the peninsula and in the region," foreign ministry spokesman Liu Weimin said in a statement.
He also called on all sides to maintain "contact and dialogue" in the brief statement, which gave no other details.
Russia, which shares a border with the errant communist state, said the launch had been a breach of UNSC resolutions. Foreign Minister Sergei Lavrov joined China and India in calling for "restraint".
"We are convinced that the reaction to these challenges needs to be exclusively diplomatic and political," Lavrov said alongside his Chinese and Indian counterparts after a meeting in Moscow.
Foreign ministers from the Group of Eight powers swiftly condemned North Korea and said they would consider action at the UN Security Council.
"We are ready to consider, with others, taking measures responding to all activities of the DPRK that violate UN Security Council Resolutions, and calling for appropriate response by the United Nations Security Council," the G8 said, referring to the North by its official name, the Democratic People's Republic of Korea.
The Group of Eight - Britain, Canada, France, Germany, Italy, Japan, Russia and the United States - did not spell out what measures they would seek at the world body.
The European Union branded the failed launch a "dangerous and destabilising" action.
"Regardless of its stated purpose, today's attempted launch is a clear violation of the DPRK's international obligations as set out in particular under UN Security Council Resolution 1874," EU foreign policy chief Catherine Ashton said in a statement.
The 15-member UN Security Council was to meet in emergency session on Friday "to decide its next step" following the action, a UN diplomat said.
Australia was in lockstep with its Western allies, with Prime Minister Julia Gillard urging a "robust response" from the Security Council.
"Regardless of its outcome, this launch was provocative and dangerous," she said in a statement.
Taiwan, which lies close to the flight path, expressed "regret" over the launch and urged Pyongyang "to stop taking actions that heighten regional tensions".
Malaysia pronounced itself "gravely concerned" and Singapore called the launch "regrettable".
The Philippines, which had diverted flights to keep them away from the intended ditching area of the rocket, said Pyongyang should "cease any future provocation".
But Indonesia struck a cautious note, urging calm in the wake of the launch.
"At this critical juncture, it is important that all project calm and exercise maximum restraint," Indonesian Foreign Minister Marty Natalegawa said.
"More than ever, it is vital that diplomacy and dialogue be placed at the forefront in order to ensure peace and stability on the Korean peninsula."