SEOUL - China's Vice President Wang Qishan plans to attend the inauguration of South Korean President-elect Yoon Suk-yeol next week, Yoon's team announced on Friday, as Beijing tries to expand its influence in the region.

Wang's planned attendance comes as Yoon has vowed to strengthen South Korea's alliance with the United States in the face of growing nuclear and missile threats from North Korea, and as Washington pushes to keep Beijing's growing influence in check.

The United States is sending second gentleman Douglas Emhoff as the head of its delegation to the ceremony, slated for Tuesday in Seoul, according to the president-elect's team.

Senior foreign affairs and security officials were not included in the U.S. delegation; President Joe Biden plans to visit Seoul the following week for talks with Yoon.

From Japan, former Prime Minister Yukio Hatoyama will attend the inauguration, and Tokyo is also expected to send a minister-level official, the presidential transition team said, adding that the process has not been finalised.

Yoon takes office amid myriad challenges, with North Korea conducting weapons tests ahead of his inauguration.

On Wednesday, North Korea fired a ballistic missile toward the sea off its east coast in its 14th known test this year, after leader Kim Jong Un vowed to develop the country's nuclear forces "at the fastest possible speed."

(Reporting by Soo-hyang Choi and Joori Roh; Editing by Tom Hogue and Gerry Doyle)