North Korea said it tested a miniaturized nuclear warhead on Friday as protection against "threats and sanctions" from hostile elements, according to the isolated state's official news agency.



North Korea proved that the country could make "standardized" nuclear warheads and mount them on "strategic ballistic rockets."

In a rambling statement, North Korea said the successful test was a demonstration of the country's preparation for retaliation against its enemies, chiefly "U.S.-led hostile forces who have gone desperate in their moves to find fault with the sovereign state's exercise of the right to self-defense while categorically denying the DPRK's strategic position as a full-fledge nuclear weapons state."

The statement from the rogue nation came after multiple global agencies detected seismic activity in North Korea on Friday morning local time. Prior to North Korea's confirmation of the test, both Japanese and South Korean authorities said that they believed the explosion, which caused an earthquake, was the result of fifth nuclear test by their neighbor.

The blast caused by the test was bigger than the one caused by North Korea's nuclear test in January, according to the South Korean meteorological agency.

The agency said the "man-made" quake emitted energy double that emitted by the January nuclear test. The South Korean military said the magnitude 5.0 seismic wave would indicate a 10 kilotonne blast, which would be the isolated nation's largest ever, local news agency Yonhap reported.

Meanwhile, Jeffrey Lewis of the Middlebury Institute of International Studies told Reuters that the seismic activity detected in North Korea indicated a blast of 20 kilotonnes to 30 kilotonnes, which he said would make the test larger than the nuclear bomb the U.S dropped on Hiroshima in World War II and possibly even larger than the one dropped on Nagasaki soon after.