Governments and leaders from around the world are condemning North Korea's latest nuclear test.
United Nations Secretary-General Ban Ki-moon described the move as "deeply destabilizing." He says it is a "clear and grave violation" of sanctions banning Pyongyang from nuclear and missile tests.
U.S. President Barack Obama called the test "highly provocative." In a statement, he said it undermines regional stability and will not make North Korea safer. He called for "swift and credible" international action in response.
NATO said the nuclear test, combined with North Korea's December missile launch, poses a "grave threat to international peace, security and stability."
China, North Korea's main ally, expressed what it called "firm opposition" to the test. Beijing's foreign ministry urged Pyongyang to abide by its non-nuclear commitment, saying the issue should be resolved in the framework of long-stalled, six-nation de-nuclearization talks.
Even Iran, which the U.S. believes is pursuing a nuclear weapons program of its own, criticized the launch. A foreign ministry spokesperson said although all countries have the right to make use of nuclear activities "for peaceful purposes," Tehran hopes all weapons of mass destruction and nuclear arms will be destroyed.
South Korea called the test "an unacceptable threat to peace and stability" and a "head-on challenge" to the international community. Seoul says Foreign Minister Kim Sung-hwan agreed with U.S. Secretary of State John Kerry during a telephone call to take "swift and unified action" at the U.N. Security Council, which is meeting later Tuesday to discuss the test.
In Japan, Prime Minister Shinzo Abe said Tokyo would consider its own new sanctions against North Korea in response to the test, which he called "extremely regrettable."
The European Union called the move a "blatant challenge" to nuclear non-proliferation. Catherine Ashton, the High Representative for Foreign Affairs, said in a statement that North Korea should refrain from further provocative actions.
Elsewhere, British Foreign Minister William Hague says his country will push for a "robust" international response to the North Korean test.
French President Francois Hollande said he condemns the test "in the strongest terms," and promised to back "strong action" by the U.N. Security Council.
Moscow also "decisively" condemned the test as a violation of North Korea's international obligations.
German Foreign Minister Guido Westerwelle said the international community should respond to the provocation with a "clear stance," saying further sanctions against Pyongyang must be considered.
India's Ministry of External Affairs said it views the test as a "matter of deep concern."