JAPAN: North Korea has miniaturized nukes small enough to fit on its ballistic missiles, is a 'serious and imminent threat'

North Korea has miniaturised nuclear warheads and made them small enough to fit on ballistic missiles, Japan believes. 
Tokyo defence chiefs warn in a new white paper that North Korea's military activities pose a 'serious and imminent threat'. 

In last year's report Japan said it was 'possible' that North Korea had achieved miniaturisation, but Tokyo now appears to have upgraded its assessment, according to Japanese newspaper Yomiuri. 
Japan is seen as a 'primary target' of nearby North Korea's weapons capabilities and fears that Pyongyang's nuclear programme 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 denuclearisation 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.