The U.N. Security Council strongly condemned North Korea Tuesday for its nuclear test in defiance of security council resolutions and pledged further action. The move came hours after North Korea confirmed that it successfully conducted its third nuclear test. The test registered as a 5.1-magnitude seismic event and the U.S. Office of the Director of National Intelligence said the country had "probably conducted an underground nuclear explosion" with a yield of "several kilotons," NBC News reported. It came on the eve of President Barack Obama's State of the Union address. Obama called the test a "highly provocative act." "North Korea's nuclear weapons and ballistic missile programs constitute a threat to U.S. national security and to international peace and security," Obama added. According to Reuters, the North said its test employed a miniaturized device that had "greater explosive force" than its two previous tests, and experts believe plutonium was used again. The North's test was "significantly larger" than its first two tests in 2006 and 2009, U.S. officials confirmed to NBC News. But the bomb was still much weaker than the one the U.S. dropped on Hiroshima, Japan, in 1945, with a 15-kiloton yield according to The New York Times. North Korea's completion of its third nuclear test fulfilled a vow the reclusive communist state had made last month, in protest of toughened U.N. sanctions over its December rocket launch.