If NK go ahead with a nuke test in the Pacific (i.e. Don't back down from recent war of words) would this be seen as a clear and present danger to the US prompting a pre emptive and overwhelming nuke strike?
It's impossible for any one to take out all of NKs weapons, without them first having time to completely level places in South Korea, killing thousands if not millions. That's why trumps rhetoric is pointless.
I don't think the US will use nuclear weapons before NK has killed people with them.
Trump said that if the US did start launching then NK would be destroyed.