China wants to win the hearts and minds of the Taiwanese people, so in the past few months they have said very little about reunification.
China wants to strengthen its ties with North Korea, and to reassure North Korea that China considers it an important neighbor.
U.S. worries about China will still grow. China can try to make the United States feel at ease, but it's all doubtful from the U.S. viewpoint. Some issues cannot be resolved at all at this stage.
For China nowadays, North Korea is important for strategic, not ideological, reasons.
In the future, China will provide more international public goods in many areas.