Of course, the entire world is skeptical...and that includes Kim.
It is possible to imagine a comprehensive US grand strategy that pressures China to play a more decisive role in helping denuclearize North Korea and offers North Korea a palatable alternative to nuclear weapons. This path would require thinking strategically, supporting and deploying America's combined diplomatic, economic and military power, embracing the Trans Pacific Partnership, working closely with allies and doing a host of other things the Trump administration has proven wholly incapable of doing.