A government official reportedly says Japan will request an emergency U.N. Security Council meeting to discuss North Korea's nuclear and missile tests.

North Korea says it carried out an underground nuclear test today, reportedly many times larger than a 2006 test.

South Korea's Yonhap news agency reports the regime also test-fired a short-range, ground-to-air missile.

Japan's chief government spokesman says the test "would clearly violate U.N. Security Council resolutions." He says Japan won't tolerate it.

The Kyodo news agency quotes Japan's Vice Foreign Minister about the meeting.

North Korea, incensed by the condemnation of an April 5 launch thought to be a long-range missile test, had warned that it would restart it rogue nuclear program, conduct an atomic test and carry out long-range missile tests.