His people are already poor and starving, until China buckles down and really puts the screws to him it won’t matter what the UN does.
They WILL call this an Act Of War!
Why would that make any difference? China and NoKo aren't kissin' cousins. Oh, b/c China has a bigger army? That doesn't seem to bother NoKo one bit.
Remember, it wasn't that long ago that China was sending them train loads of food, and the NoKos were keeping it(them) -- the food and the trains! China barked at them that they wanted their *&^$! trains back...or else. Kim & Co. essentially brush them off with an airy wave of the hand. China ranted and raved a bit more, then pretty much let the whole matter drop.
IOW, China vis-a-vis NoKo is no silver bullet.