and engines and honing their targeting and guidance systems. the u.s. believes kim and his generals could be able to place a miniaturized warhead on top of a missile some time next year and experts say they're just a couple of steps away from demonstrating a full-fledged capability to hit the continental u.s. with a nuclear-tipped missile. >> the one thing they could do to demonstrate an end-to-end nuclear capability is to put an actual nuclear weapon on the top of a missile into the pacific and actually detonate it out there. to get there, we think there might be some things to work out, such as miniaturization and reentry so it gets through the atmosphere without burning up. >> reporter: analysts say north korea's next provocation may in fact be placing a nuclear warhead on top of a missile and detonating it somewhere over the pacific ocean in an above ground nuclear test. they say if that happens, when that happens, that will be a game-changer and may, in fact, force the u.s., japan and south