I never thought that a deal would happen. Frankly, Trump is doing it wrong.
If I were president I would get with Japan, South Korea and Australia and privately tell the Chinese that, unless North Korea gets rid of their nukes, that the aforementioned nations would create their own nuclear arsenals. I would also tell the Chinese that, in the event that North Korea used a nuke on us or one of our friends, that it would be considered an attack by China and would require a nuclear response against Beijing and other cities.
North Korea is nuclear because China is ok with it. If China didn't want them to have nukes, they wouldn't have them. It's that simple.
Yes, let's just escalate the whole mess, glad hand out nukes to your allies like candy at a birthday party, and hope nobody gets stupid with them, and then threaten China with thermo-nuclear war. What could possibly go wrong with this plan?