I believe China hates the thought of losing their yapping Chihuahua, and told him so.
It's difficult to 'read' China. They just unilaterally lowered their tariffs on certain products and indicate they don't wish a 'Trade War' with Pres. Trump.
The general feeling is that Kim had his a$$ handed to him by Ping after the mountain site collapse and radiation leak.
He doesn't want to end up like Libya's Gaddafi and wishes to introduce China-style version of Capitalism to calm his People and his enemies.