I’d love to see NK thumb it’s nose at China and back out, but I don’t think they can afford to.
China and Russia want NK’s ports developed for US oil amd trade and that takes US approval.
The North Koreans won’t survive without Russia and China.
And the Chinese will remind them they agreed to this denuclearization process.
They’re entitled to change their minds but they won’t get security guarantees then.
Noth Korea is not to be trusted to keep its word. They have played this brinksmanship game before.
President Trump is not a patsy. They will find out that soon enough.
I think the NK of the 1990s would have easily backed out and walked away. The crafted method of downsizing their access to global markets, has turned this into a very different NK, with limited options. China has moved on, and doesn’t have the supportive nature that it had twenty years ago.