North Korea said Monday it had performed its first-ever nuclear weapons test, setting off an underground blast in defiance of international warnings and intense diplomatic activity aimed at heading off such a move.
An official at South Korea's seismic monitoring center confirmed a magnitude-3.6 tremor felt at the time North Korea said it conducted the test was not a natural occurrence. Australia also said there was seismic confirmation that North Korea conducted a nuclear test.
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.
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.