It means the Chinese can fabricate an excuse at their convenience.
I think you are correct matt1234. It looks like the ChiComs are going to work with Trump to shut down the NK nuclear program.
BINGO!
Meanwhile the Chinese are covering all bases by engaging in talks with South Korea. Depending on how one interprets the joint declaration they have made, they might be developing a situation in which if north and south are reunited there will NOT be a hostile government north of the Yalu River.