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 Barack 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."
North Korea says it successfully detonated a miniaturized nuclear device at a northeastern test site Tuesday, defying U.N. Security Council orders to shut down atomic activity or face more sanctions and international isolation.
Obama says such efforts "do not make North Korea more secure." Instead, he says, North Korea has "increasingly isolated and impoverished its people through its ill-advised pursuit of weapons of mass destruction."
SEOUL, South Korea -- A South Korean Defense Ministry spokesman says Seoul believes that a nuclear test caused an earthquake in North Korea near the site of two previous atomic tests.
Kim Min-seok says North Korea informed China and the United States of its plans to conduct a nuclear test.
Kim says that shortly before noon Tuesday an earthquake was detected in North Korea.