North Korea's latest nuclear test drew swift and widespread international censure Tuesday, and Iran, while stopping short of condemnation, called for all the world's nuclear weapons to be destroyed.
"We think we need to come to a point where no country will have any nuclear weapons," Iranian Foreign Ministry Spokesman Ramin Mehmanparast told a weekly news conference when asked about the test. "All weapons of mass destruction and nuclear arms need to be destroyed."
Mehmanparast added that all countries should be able to use nuclear technology for peaceful purposes.
Iran is under UN sanctions over its own nuclear program, which the United States and some of its allies suspect is aimed at developing an atomic weapons capability. Iran denies that charge and says its program is purely peaceful.
North Korea said its test on Tuesday had "greater explosive force" than the 2006 and 2009 tests, which were widely seen as small-scale.
US President Barack Obama branded the test a "highly provocative act" that hurt stability in the region, and called Pyongyang's nuclear program a threat to American and international security.
"The danger posed by North Korea's threatening activities warrants further swift and credible action by the international community. The United States will also continue to take steps necessary to defend ourselves and our allies," Obama said in a statement.
"We will strengthen close coordination with allies and partners and work with our Six-Party partners, the United Nations Security Council, and other UN member states to pursue firm action," he said. The UN Security Council was to meet later in the day to discuss its response to the move.
China, North Korea's greatest ally, added its own criticism, urging Pyongyang to abide by its non-nuclear commitment and not take any actions that would worsen the situation on the Korean peninsula.
"It is China's firm stance to realize non-nuclearization for the Korean peninsula and prevent nuclear proliferation and maintain peace and stability in northeast Asia", the Chinese Foreign Ministry said in a statement.
The United Nations, Japan, Britain and Russia on Tuesday also strongly condemned the test, with UN chief Ban Ki-moon saying it was "deplorable" that Pyongyang had defied international appeals to refrain from such provocative acts.
South Korea confirmed the test Tuesday, and said the size of the seismic activity indicated a nuclear explosion slightly larger than the North's two previous tests at 6-7 kilotons, although that is still relatively small. The Hiroshima bomb was around 20 kilotons.
The US Geological Survey said that a seismic event measuring 5.1 magnitude had occurred on Tuesday, with North Korea later confirming the nuclear test.
"It was confirmed that the nuclear test that was carried out at a high level in a safe and perfect manner using a miniaturized and lighter nuclear device with greater explosive force than previously did not pose any negative impact on the surrounding ecological environment," KCNA said.
"The Secretary-General condemns the underground nuclear weapon test conducted by [North Korea] today," Ban's spokesman Martin Nesirky said in a statement. "It is a clear and grave violation of the relevant Security Council resolutions."
In Moscow, a Foreign Ministry source struck a similar note, telling the Interfax news agency that Russia "decisively condemned" North Korea's nuclear test on Tuesday as a violation of Pyongyang's international obligations.
"We condemn these actions by North Korea and view them together with the ballistic rocket launch carried out earlier [in December] as a violation of the corresponding UN Security Council resolution," the ministry source said.
Moscow used its vote on the UN Security Council last month to support a resolution that tightened sanctions against Pyongyang in response to its December rocket launch.
British Foreign Secretary William Hague also "strongly" condemned the nuclear test Tuesday, and said Britain would press for a robust response to the test by the Security Council.
"I strongly condemn this development, which is a violation of UN Security Council Resolutions 1718, 1874 and 2087," Hague said in a statement.
"The UK will begin urgent consultations with Security Council partners calling for a robust response to this latest development."
Meanwhile, the US Office of the Director of National Intelligence on Tuesday said only that intelligence agencies are aware of a "seismic event," which North Korea has claimed was the nuclear test.
"The intelligence community is aware of a seismic event with explosive characteristics in North Korea and we are evaluating all relevant information," the office said in a statement.