WASHINGTON (AP) - 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 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 Korean Central News Agency said the test was conducted safely but with "great explosive power." It said the test is aimed at coping with "ferocious" U.S. hostility that undermines the North's peaceful, sovereign right to launch satellites. Last month, North Korea's National Defense Commission said the United States 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."
Defense Secretary Leon Panetta, in remarks Tuesday morning to Pentagon workers gathered in the building's courtyard, said the U.S. is going to have to continue to deal with rogue states like North Korea.
"We just saw what North Korea has done in these last few weeks, a missile test and now a nuclear test," he said. "They represent a serious threat to the United States of America, and we've got to be prepared to deal with that. "
The White House said Obama, who is scheduled to deliver his State of the Union address Tuesday evening, had already intended to mention North Korea in the speech, describing the North's action as part of a pattern of provocative behavior that has undercut its government's legitimacy.
"The president will say that the only way North Korea will rejoin the world community is if they stop these threats and live up to their international obligations," said Tommy Vietor, a spokesman for the White House's National Security Council.
The chairman of the House Foreign Affairs Committee, California Republican Ed Royce, released a statement Tuesday calling on the Obama administration to "replace its failed North Korea policy" and issue "stringent sanctions" against North Korean leader Kim Jong Un's regime. "Otherwise, the grave North Korean threat to the region and the United States will only grow," Royce said.
And House Intelligence Committee chairman Mike Rogers, R-Mich., added that the U.S. must take a new approach to dealing with North Korea. "The key to stemming North Korea's cycle of provocation is to seriously engage the Chinese in exercising leverage over their neighbor," he said.
The U.N. Security Council will 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 will begin at 9 a.m. EST.
Senior White House adviser Valerie Jarrett said she expects the international community "will have a very firm response."
She said in an appearance on NBC's "Today" show that North Korea's move presents a threat to the region and to the United States. "It actually is not in the best interests of North Korea," she said.
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.
On Tuesday, China expressed firm opposition to the test but called for a calm response by all sides.