Quote"North Korea was forced to develop its nuclear arsenal because of the U.S.'s hostile policy against Korea," she said. "However, as a peaceful nation and a nuclear powered nation, North Korea will be a responsible state and will not use its nuclear power before [an attack] and will not transfer the technology to others."
There was some skepticism about the claim, with nuclear analysts noting that the yield appeared to be similar to North Korea's three previous atomic tests, rather than the "enormous" size that would be expected if it had been a thermonuclear test.
Either way, Pyongyang's provocative action will present a new challenge to the outside world, which has struggled to find ways to end North Korea's nuclear defiance.
source: https://www.washingtonpost.com/world/signs-of-possible-nuclear-test-in-north-korea/2016/01/05/d8f300e7-995d-40de-a082-3171f0cc0ea9_story.html?wpisrc=al_alert-COMBO-world%252Bnation