Report: North Korea has miniaturized nuclear warheads

The findings are likely to deepen concerns about an evolving North Korean military threat that appears to be advancing far more rapidly than many experts had predicted. U.S. officials last month concluded that Pyongyang is also outpacing expectations in its effort to build an intercontinental ballistic missile capable of striking cities on the American mainland.

While more than a decade has passed since North Korea’s first nuclear detonation, many analysts believed it would be years before the country’s weapons scientists could design a compact warhead that could be delivered by missile to distant targets. But the new assessment, a summary document dated July 28, concludes that this critical milestone has already been reached.