Not the best diplomatic move of the current administration.
The US is on the path of losing SKs favor to NK
https://www.reuters.com/article/us-o...-idUSKBN1FU05F
If fine if the US wants yields its influence to a unified Korea or at least a cooperative SK and NK. Terrible if the US wants to maintain its strategic position in the area. At this point the US has to work towards convincing SK to maintain US interests, that the US can somehow offer a better path to peace. Hopefully the US isnt using its Cold War playbook, which means the US would rather destabilize the entire region than to see itself left out of peace talks.
NK will definitely paint the US as the spoiler of peace though.
- - - Updated - - -
Diplomacy doesnt work if you refuse to speak to the opposition.