North Korea will have enough material for about 20 nuclear bombs by the end of this year with enhanced uranium-enrichment facilities and an existing stockpile of plutonium, according to new assessments by weapons experts.
The revelations came as North Korea accused the United States of pushing the Korean peninsula to "the point of explosion" after it dispatched two huge bombers in a show of force against North Korea.
The American supersonic B-1B Lancers flew over South Korea on Tuesday as the US pledged its "unshakeable commitment" to defend its allies in the region, following North Korea's fifth and largest-ever nuclear test conducted last week.