Wenran Jiang is the one of the  most naïve persons I have read in a long time.  He doesn't seem at all familiar with the results of past negotiations with North Korea.  They will agree to almost anything and they simply ignore their obligations when they have what they wanted.  
Clinton found this out last time he provided food in exchange for an end to N. Korea's nuclear program.  Once the food was delivered and the famine ended, N. Korea simply continued their program.
They see negotiations as a weakness on the part of the West and a strategic tool for themselves.  
Power is the only thing they understand, and if starving the nation until the generals revolt, then so be it.