The Chinese government has appointed a top security official in Hong Kong as the chief of its Liaison Office in the territory.

Zheng Yanxiong has been the director of the Office for Safeguarding National Security set up under the 2020 National Security Law for Hong Kong.

Zheng is also being appointed as an adviser to the Committee for Safeguarding National Security in Hong Kong, which assesses the security situation in the territory and draws up policies.

Under the national security law, Hong Kong's Chief Executive nominally serves as the head of the committee, which is under the supervision of the central government in Beijing.

Zheng will in effect supervise Chief Executive John Lee.

Zheng has maintained a hardline stance as the chief of the security agency in Hong Kong, cracking down on antigovernment protests for more than two years.

His promotion to the head of the Chinese government's top representative office in Hong Kong signals Beijing's intention to tighten its control over the territory.