A report says that North Korea has miniaturized nuclear warheads to the extent that they can be launched on medium-range missiles.

British daily The Times quoted Daniel Pinkston of the International Crisis Group as saying that the North acquired such technology toward the end of last year.

He also said that the danger lies with hard-to-detect shorter-range weapons, including variants of the Scud, which could reach South Korea, and the Nodong, which could strike Japan.

He added, however, that the long-range Daepodong-Two rocket the North Korea fired earlier this month is an unsuitable vehicle for a nuclear bomb because it takes too long to assemble, fuel and arm.