SEOUL, South Korea - North Korea said Monday it had conducted its first nuclear weapons test, setting off an underground blast in defiance of international warnings and intense diplomatic activity aimed at heading off such a move.
U.S. and South Korean officials could not immediately confirm the North Korean report but the
U.S. Geological Survey said it recorded a seismic event with a preliminary magnitude of 4.2 in northeastern North Korea that coincided with the country's announced nuclear test.
The Colorado-based agency said it was unable to tell whether the event was the result of an atomic explosion or a natural earthquake.
Condemnation from the region came swiftly. Japan's top government spokesman said if confirmed, the North Korean test would post a serious threat to the stability in the region and a provocation.
China, the North's closest ally, said Beijing "resolutely opposes" the North Korean nuclear test and hopes Pyongyang will return to disarmament talks.
South Korea's Defense Ministry said the alert level of the military had been raised in response to the claimed nuclear test.
The U.N. Security Council is expected to discuss the reported North Korean test on Monday, and the United States and Japan are likely to press for a resolution imposing additional sanctions on Pyongyang.
A resolution adopted in July after a series of North Korean missile launches imposed limited sanctions on North Korea and demanded that the reclusive communist nation suspend its ballistic missile program — a demand the North immediately rejected.
The resolution bans all U.N. member states from selling material or technology for missiles or weapons of mass destruction to North Korea — and it bans all countries from receiving missiles, banned weapons or technology from Pyongyang.
The North said last week it would conduct a test, sparking regional concern and frantic diplomatic efforts aimed at dissuading Pyongyang from such a move. North Korea has long claimed to have nuclear weapons, but had never before performed a known test to prove its arsenal.
The North's official Korean Central News Agency said the underground test was performed successfully.
"It marks a historic event as it greatly encouraged and pleased the ... people that have wished to have powerful self-reliant defense capability," the KCNA statement said.
"It will contribute to defending the peace and stability on the Korean Peninsula and in the area around it."
South Korean intelligence officials said a seismic wave had been detected in North Hamkyung province, according to South Korea's Yonhap news agency. It said the test was conducted at 10:36 a.m. (9:36 p.m. EDT Sunday) in Hwaderi near Kilju city on the northeast coast, citing defense officials.
North Korean scientists "successfully conducted an underground nuclear test under secure conditions," the KCNA report said, adding this was "a stirring time when all the people of the country are making a great leap forward in the building of a great prosperous powerful socialist nation."
On Sunday night, U.S. government officials said a wide range of agencies were looking into the report of the nuclear test, which officials were taking seriously.
South Korean President Roh Moo-hyun has convened a meeting of security advisers over the issue, Yonhap reported, and intelligence over the test has been exchanged between concerned countries.
Kyodo News agency reported that the Japanese government has set up a taskforce in response to reports of the test.
The North has refused for a year to attend international talks aimed at persuading it to disarm. The country pulled out of the Nuclear Nonproliferation Treaty in 2003 after U.S. officials accused it of a secret nuclear program, allegedly violating an earlier nuclear pact between Washington and Pyongyang.
Speculation over a possible North Korean test arose earlier this year after U.S. and Japanese reports cited su****ious activity at a suspected underground test site. http://news.yahoo.com/s/ap/20061009/...koreas_nuclear