Nuking any US territory will force the US to nuke NOKO. Testing an open air weapon will fry someones’ electronics ... (things have changed since the West did open air testing) ... and force DJT to either do nothing but talk and appear weak (inviting a directed strike on the US by NOKO) or strong and wipe NOKO off the map. There is, at that point, no Third Way.
DJT either takes NOKO out or he and we get fried. Jabbering and pieces of paper are no threat to Kim. He will proceed as he plans: first the US, then SOKO and Japan. Perhaps these are his plans, or perhaps he is just fulfilling Xi’s plans.
Kim won't do that. Until NK actually nukes someone the US will NOT nuke NK.