The only way I would be okay is if the USA had irrefutable proof that North Korea was about to launch missiles at allied population centers and not just posturing. Then a preemptive strike to save the lives of our allies would be acceptable.
Attacking without such proof would not only cause bloodshed that might have been avoided, but ratchet up tensions in the region (especially with China), and paint the USA as too aggressive.
If North Korea attacks first, then the USA and allies would have a free hand to destroy that regime as nobody could argue that it didn't present a clear threat.
If North Korea is only posturing then, economic sanctions should be continued until the populace has had enough and the regime collapses from internal pressure. However, contingent to that, there could be no humanitarian aid given until the Kims are out of power. It sounds harsh, but even just supplying basic needs would allow the Kims to continue their misuse of national resources and the abusive programs that keep them in control.