U.S. President Barack Obama on Tuesday called North Korea's latest nuclear test a "highly provocative act" that threatens U.S. security and international peace.
"The danger posed by North Korea's threatening activities warrants further swift and credible action by the international community," Obama said in a statement issued early Tuesday. "The United States will also continue to take steps necessary to defend ourselves and our allies."
North Korea said it had successfully detonated a miniaturized nuclear device at a northeastern test site Tuesday. South Korean, U.S. and Japanese seismic monitoring agencies said they detected an earthquake in North Korea with a magnitude between 4.9 and 5.2.
North Korea's official state media said the test was conducted in a safe manner and was aimed at coping with "outrageous" U.S. hostility that "violently" undermined its peaceful, sovereign right to launch satellites. Last month, North Korea's National Defense Commission said the U.S. was its prime target for a nuclear test and long-range rocket launches.
"These provocations do not make North Korea more secure," Obama said. "Far from achieving its stated goal of becoming a strong and prosperous nation, North Korea has instead increasingly isolated and impoverished its people through its ill-advised pursuit of weapons of mass destruction and their means of delivery."
Taking the opportunity to advance its own agenda, Iran also issued a response to the North Korean detonation.
"We need to come to the point where no country has any nuclear weapons and at the same time all weapons of mass destruction and nuclear arms need to be destroyed," Foreign Ministry spokesman Ramin Mehmanparast said. "At the same time, all countries should have the right to make use of nuclear activities for peaceful purposes."
The U.N. Security Council was scheduled to hold an emergency meeting Tuesday morning on North Korea's nuclear test. South Korea's U.N. mission informed reporters early Tuesday that the closed-door meeting would begin at 9 a.m. EST (4 p.m. Israel time).
On Monday, U.S. Secretary of State John Kerry discussed North Korea's "continued provocative rhetoric" in a phone call with China's Foreign Minister Yang Jiechi. That followed earlier conversations with Kerry's counterparts from Japan and South Korea, key U.S. allies in the region.
State Department spokeswoman Victoria Nuland said the three conversations "were remarkably similar" on the importance of implementing the commitments of a January U.N. resolution that toughened sanctions against Pyongyang and warned of "significant action" if it conducted a nuclear test. That resolution was supported by China, North Korea's only major ally.
U.N. Secretary-General Ban Ki-moon also condemned the test, saying that "it is deplorable that Pyongyang defied the strong and unequivocal call from the international community to refrain from any further provocative measures."
British Foreign Secretary William Hague echoed world leaders by saying, "North Korea's development of its nuclear and ballistic missile capabilities poses a threat to international and regional security. Its repeated provocations only serve to increase regional tension, and hinder the prospects for lasting peace on the Korean peninsula."