Nothing short of REGIME CHANGE (for the better) will make ANY DIFFERENCE WITH THIS ROGUE STATE, Republican and Democrat Administration alike.
Now the question is how to provide goods population will undoubtedly want to purchase with new load of money. If there is no supply of goods, N. Korea risks hyperinflation. Or goods will get really scarce, and hyperinflation will happen in black market. Either way, it will happen.
Therefore, he wants outsiders to provide the goods. This is probably why he now sounds nice. It has nothing to do with abandoning his nukes. Another sucker move to extort lots of goodies in exchange for going back to some negotiation posture similar to what they did prior to 2008.