South Korea says it wants a strong U.N. Security Council response to North Korea's latest nuclear test, which the United States has characterized as a direct and reckless challenge to the international community. Meantime, President Barack Obama has condemned North Korea's nuclear test, saying the international community must stand up to North Korea on the nuclear issue.
A White House statement is calling North Korea's nuclear test "a matter of grave concern" that "warrants action by the international community."
Earlier Sunday, South Korean Presidential Spokesman Lee Dong-kwan called North Korea's nuclear test Monday a "serious threat to peace and stability on the Korean peninsula."
He says South Korea will work together with the United States, Japan, China and Russia to seek a response at the United Nations Security Council.
Earlier Monday, shortly after a 4.5 magnitude seismic event was detected in northeastern North Korea, North Korean official media confirmed a test had taken place.
A North Korean newsreader says the country "successfully conducted one more underground nuclear test," demonstrating what Pyongyang calls its "self-defensive nuclear deterrent" to the entire world.
This is North Korea's second nuclear test. Scientists say it took place near the site of North Korea's first test in 2006. That test drew condemnation from the international community as well as the passage of a punitive United Nations Security Council Resolution.
The test does not come as a complete surprise. North Korea warned it would conduct more nuclear tests last month, after the Security Council condemned its launch of a long-range rocket. It has since ejected international nuclear inspectors and announced its permanent withdrawal from multinational talks aimed at ending its nuclear programs. The North has also said it would recommence the process of deriving weapons-grade material from spent nuclear fuel.
Lee Jung-hoon, a professor of political science at Seoul's Yonsei University, says North Korea probably conducted the test because it felt it had nothing to fear.
Lee says North Korea's long-range rocket launch in April drew no real sanctions from the United Nations Security Council, just a warning. He says that probably emboldened the North, by making it difficult to take the United States and its partners seriously.