Updated 2:10 a.m. EST
Pyongyang, North Korea North Korea successfully detonated a miniaturized nuclear device at a northeastern test site Tuesday, state media said, defying U.N. Security Council orders to shut down atomic activity or face more sanctions and international isolation.
The underground explosion could take North Korea a big step closer to its goal of building a nuclear warhead small enough to be mounted on a long-range missile that could threaten the United States.
The White House is calling North Korea's latest nuclear test a "highly provocative act" that threatens U.S. security and international peace.
In a statement issued early Tuesday, President Obama promises to "continue to take steps necessary to defend ourselves and our allies." He also urges "swift and credible action by the international community."
Mr. Obama says such efforts "do not make North Korea more secure." Instead, he says, Pyongyang Korea has "increasingly isolated and impoverished its people through its ill-advised pursuit of weapons of mass destruction."
Official North Korean state media said the test was conducted in a safe manner and is aimed at coping with "outrageous" U.S. hostility that "violently" undermines the North's peaceful, sovereign rights to launch satellites. North Korea faced sanctions after a December launch of a rocket the U.N. and Washington called a cover for a banned missile test.
The United Nations Security Council called an emergency meeting for Tuesday morning to take up the test.
U.N. Secretary-General Ban Ki-moon condemned the test, saying it was "deplorable" that Pyongyang had defied international appeals to avoid such provocative acts, the Reuters news agency reports.
And Russia "decisively condemned" the test, via its Interfax news agency, Reuters says.
The North said it used a "lighter, miniaturized atomic bomb" that still has more explosive force than devices tested previously.
The United States Geological Survey said earlier Tuesday that it had detected a 4.9 magnitude earthquake in North Korea.
The nuclear test is North Korea's first since leader Kim Jong Un took power in December 2011 following the death of his father, Kim Jong Il, and marks a bold statement for the young leader as he unveils his domestic and foreign policy for a country long estranged from the West.
Experts say regular tests are needed to perfect North Korea's goal of building nuclear warheads small enough to be placed on long-range missiles. This atomic test -- North Korea's third since 2006 -- is expected to take Pyongyang closer to possessing nuclear-tipped missiles designed to strike the United States.
Pyongyang, North Korea North Korea successfully detonated a miniaturized nuclear device at a northeastern test site Tuesday, state media said, defying U.N. Security Council orders to shut down atomic activity or face more sanctions and international isolation.
The underground explosion could take North Korea a big step closer to its goal of building a nuclear warhead small enough to be mounted on a long-range missile that could threaten the United States.
The White House is calling North Korea's latest nuclear test a "highly provocative act" that threatens U.S. security and international peace.
In a statement issued early Tuesday, President Obama promises to "continue to take steps necessary to defend ourselves and our allies." He also urges "swift and credible action by the international community."
Mr. Obama says such efforts "do not make North Korea more secure." Instead, he says, Pyongyang Korea has "increasingly isolated and impoverished its people through its ill-advised pursuit of weapons of mass destruction."
Official North Korean state media said the test was conducted in a safe manner and is aimed at coping with "outrageous" U.S. hostility that "violently" undermines the North's peaceful, sovereign rights to launch satellites. North Korea faced sanctions after a December launch of a rocket the U.N. and Washington called a cover for a banned missile test.
The United Nations Security Council called an emergency meeting for Tuesday morning to take up the test.
U.N. Secretary-General Ban Ki-moon condemned the test, saying it was "deplorable" that Pyongyang had defied international appeals to avoid such provocative acts, the Reuters news agency reports.
And Russia "decisively condemned" the test, via its Interfax news agency, Reuters says.
The North said it used a "lighter, miniaturized atomic bomb" that still has more explosive force than devices tested previously.
The United States Geological Survey said earlier Tuesday that it had detected a 4.9 magnitude earthquake in North Korea.
The nuclear test is North Korea's first since leader Kim Jong Un took power in December 2011 following the death of his father, Kim Jong Il, and marks a bold statement for the young leader as he unveils his domestic and foreign policy for a country long estranged from the West.
Experts say regular tests are needed to perfect North Korea's goal of building nuclear warheads small enough to be placed on long-range missiles. This atomic test -- North Korea's third since 2006 -- is expected to take Pyongyang closer to possessing nuclear-tipped missiles designed to strike the United States.