Trump is smart to leverage trade and the "one China" policy to persuade Xi to rein in Kim. 
Now Xi also knows Trump is willing to act to remove the NK threat if it becomes necessary. Trump is unpredictable where as Obama projected weakness to the world. If we're going to have a trade surplus and withhold recognition of Tiawan, we might as well get something in return. I think this is a much more effective US strategy than providing food and fuel aid as has been done in the past.