SEOUL, South Korea (AP) - South Korea is now confirming that North Korea conducted a nuclear test Tuesday.

The test, the North's third such one, was widely anticipated. Monitoring agencies around the globe had detected an earthquake that appeared to have been unnatural.

According to North's KCNA official news agency, North Korea confirmed on Tuesday it has successfully conducted a third nuclear test, saying it used a miniaturized device that had a greater explosive force than previous tests.

"It called on the KPA (Korean People's Army) to keep itself fully ready for combat and put maximum spurs to rounding off its combat preparedness in order to bolster up one-beats-a hundred combat capability. It stressed that once an order issued, the KPA should blow up the stronghold of aggression at a strike and wipe out the robber-like U.S. imperialists and South Korean puppet army to the last man and thus accomplish the historic cause of national reunification," a KRT news reader said, quoting its government.

North Korea has threatened to attack rival South Korea if Seoul joined a new round of tightened U.N. sanctions, as Washington unveiled more of its own economic restrictions following Pyongyang's rocket launch last month.

The reclusive North declared a boycott of all dialogue aimed at ending its nuclear programmer and vowed to conduct more rocket and nuclear tests, blaming the U.N. Security Council censuring it for a long-range missile launch in December.

Its December rocket launch showed it had the capacity to deliver a rocket that could travel 6,200 miles, potentially putting San Francisco in range, according to a South Korean intelligence assessment.