by Staff and wires, USA TODAY
President Obama on Tuesday called North Korea's third successful nuclear test a "highly provocative act" that "undermines regional stability" and threatens action by the international community.
He said North Korea's nuclear program constitutes "a threat to U.S. national security."
The White House released the statement early Tuesday after North Korea detonated a miniaturized nuclear device at a northeastern test site, state media said, defying U.N. Security Council orders to shut down atomic activity or face more sanctions and international isolation.
U.N. Secretary-General Ban Ki-moon also condemned the test, saying it was "deplorable that Pyongyang defied the strong and unequivocal call from the international community to refrain from any further provocative measures."
South Korea called an emergency meeting of the U.N. Security Council for 9 a. m. EST Tuesday.
South Korea's spy agency, the National Intelligence Service, warned that North Korea may conduct an additional nuclear test and launch a long-range missile if the U.N. moves to penalize it for its third nuclear test, the Yonhap news agency reported.
In a meeting with lawmakers belonging to the parliament's intelligence committee, the NIS said that it is too early to say the North has succeeded in weaponizing its nuclear technology, the news agency said..
Meanwhile, China, North Korea's only major ally, summoned the North Korean ambassador in Beijing and sternly protested the action, the Foreign Ministry said, Reuters reported.
Foreign Minister Yang Jiechi said China was "strongly dissatisfied and resolutely opposed" to the test and urged North Korea to "stop any rhetoric or acts that could worsen situations and return to the right course of dialogue and consultation as soon as possible."
Japanese Prime Minister Shinzo Abe called the test a "grave threat" that could not be tolerated.
The Russian Foreign Ministry also condemned the North Korean test.
"We insist on North Korea putting an end to all illegal actions, complying to all U.N. Security Council orders, and fully giving up nuclear missile programs," the ministry pointed out in the official statement.
Russian Foreign Minister Sergei Lavrov, speaking to reporters in Pretoria, South Africa, said Moscow will continue efforts to get North Korea to participate in six-party talks "and we believe it is important to ensure its denuclearization."
"Increasing military tensions in the region is extremely dangerous," he said.
The six party talks, which began in 2003, seek a peaceful solution to the security concerns raised by the North Korean nuclear weapons program. The talks include the United States, China, Russia, Japan, North Korea and South Korea.
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.
Official 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.
North Korea said the test was merely its "first response" to U.S. threats, and said it will continue with unspecified "second and third measures of greater intensity" if Washington maintains its hostility.
The North said it used a "lighter, miniaturized atomic bomb" that still has more explosive force than past tests.
Monitoring stations in South Korea detected an earthquake in the North with a magnitude of 4.9 and the South's Defense Ministry said that corresponds to an estimated explosive yield of 6-7 kilotons. The United States Geological Survey said earlier Tuesday that it had detected a 4.9-magnitude earthquake.
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.
China expressed firm opposition to the test but called for a calm response by all sides.
Contributing: USA TODAY's Kim Hjelmgaard; Associated Press