China has released a new list of items banned for export to North Korea , ranging from wind tunnels to plutonium, following a new round of United Nations sanctions and complaints from U.S. President Donald Trump that Beijing was not doing enough to pressure its communist neighbor. The step was seen by one leading expert on North Korea as an attempt to show that China is fully meeting its commitments, and to pre-empt any moves by the U.S. to punish Chinese companies that deal with the North.