So far I've not seen a reliable one. We recently shot one test one of ours and it worked. But NK missiles? Haven't done a damn thing. Something wrong.
I still haven’t seen any evidence they have a re-entry vehicle. I am pretty sure the missile would have to leave the atmosphere to hit the USA. I think it also would have leave the atmosphere to hit Guam or Hawaii. Missile-wise all I have seen is they have something that could hit South Korea & Japan. Setting off a bomb that is stationary deep in a tunnel is quite a bit different then having it go off after the rigors of a missile launch. (Even if the range is a few hundred miles!)