There are no longer any good North Korea solutions for the United States or its allies. North Korea has over 100 nuclear ICBM's able to target our allies and U.S. forces in South Korea, Japan, the Philippines and probably the continental U.S. This existential threat and the attendant blackmail is intolerable if the U.S. is to remain a free nation.
There are three options: negotiations (which have failed over 20 years and three presidencies due to North Korea's lying and bad faith, in spite of $1 billion of U.S. inducements); containment(although North Korea's murderous dictator is quite different from Cold War Soviet dictators who responded to this strategy); and military action by our far superior military (but which is no longer capable of a knock-out attack that prevents retaliation on an unimaginable scale). Of course, there are combinations of these three. To make a desperate situation even worse, we need strong strategic and credible world leaders in the White House and State Department where we currently have the exact opposite.
Both China and North Korea must be persuaded by carrots and sticks that their self-interest can only be served by de-nuclearizing the Korean peninsula. This means, for example, that China's fears about the impact of regime change in North Korea (and the potential flood of refugees across their border) and fear of a U.S. military (and nuclear) presence on their border, will be alleviated if they cooperate with strict economic international strangulation of North Korea, until there are good faith negotiations. The stick is the alternative reality that China will be surrounded by nuclear countries (South Korea, Japan and the U.S.) with the high probability of being dragged into a nuclear war on their doorstep which is unwinnable for North Korea and will create massive instability in China.