Guo Jiakun

Guo Jiakun is not mentioned in any of the provided news articles. Therefore, it is impossible to provide a summary of who they are, why they are newsworthy, recent events or developments related to them, or their current relevance or significance based on the given information. The articles cover a range of topics related to China's foreign relations, including its relationship with Vietnam, the US, North Korea, Japan, and Greenland, as well as trade and geopolitical issues. However, none of them mention anyone named Guo Jiakun.