Prior to Trump, no administration (no one - I think Sweden is one of the few countries that has diplomatic relations with North Korea) was willing to recognize North Korea.
Trump has elevated them from "rogue state" to "nation in good standing."
The goal has always been to let North Korea implode so that we could pick up the pieces. Now, the goal is to prop up the existing state.
RAND had a "how to win North Korea" paper just last year - they argued that you treat it like East Germany and give amnesty to fukkin' everyone and move on. That's effectively what's being negotiated here, minus the part where the North Korean regime steps down.