(Daily Mail) Tim Stickings August 21 2019 07:55 North Korea has miniaturized nuclear warheads and made them small enough to fit on ballistic missiles Japan believes. Tokyo defense chiefs warn in a new white paper that North Koreas military activities pose a serious and imminent threat. In last years report Japan said it was possible that North Korea had achieved miniaturization but Tokyo now appears to have upgraded its assessment according to Japanese newspaper Yomiuri. Japan is seen as a primary target of nearby North Koreas weapons capabilities and fears that Pyongyangs nuclear program is growing unabated experts say. The latest findings come alongside newly-released pictures which suggest a North Korean plant may be leaking hazardous waste into a nearby river. The Japanese report highlights the lack of progress on de-nuclearization talks said Vipin Narang a nuclear affairs expert at MIT. It is Japan that is most threatened and probably the primary target of such a capability he said.