This is good news, but he cannot allow China to exploit the U.S has it has for more than a decade, especially when N Korea only exists because of China. Furthermore, who suffers from all of this? N Korean citizens.
Bottom line, call them out for their currency manipulation, apply a border tariff. Do NOT trust them. The carrot in this situation should be that the sob in N Korea gets to keep power...assuming he discards his nuclear ambitions. Let's also not forget that close allies such as S Korea and Japan rely on America to stand up to China as they cannot. To me building stronger, closer business relations with Japan is far more important than backstabbing nations who openly show disdain for you.
Everyone knows that tyrants, dictators and communists respond primarily to strength. This is because they are so used to being bullies themselves that they cannot handle being the victim. They are too cowardly to face equals or those stronger and they fear losing power and facing their OWN citizens more than anything.