Hong Kong Special Administrative Region Chief Executive Carrie Lam Cheng Yuet-ngor on Friday announced a major shake-up of high-ranking officials in a bid to "efficiently" consolidate the city's opportunities presented by two national plans – the Greater Bay Area and the 14th Five-Year Plan (2021-25).

The new appointments by the State Council involve promoting John Lee Ka-chiu, secretary for security, to the position of chief secretary, replacing Matthew Cheung Kin-chung and appointing police chief Chris Tang Ping-keung to the position of security chief.

"The new appointments announced today will help us seize opportunities in a more efficient way, and that's exactly what I and the chief secretary for administration will do jointly in the months ahead," Lam said at a news briefing announcing the personnel changes.

"Now that we have restored law and order in Hong Kong, and have in place both the national security legislation and also an improved electoral system, I feel very strongly that the next 12 months are very important for Hong Kong to foster closer collaboration with the Chinese mainland as far as economic integration is concerned," she added.

Lam said future work will center around opportunities presented by the two national policies, as this year marks the beginning of the 14th Five-Year Plan and it is the third year since the outline for the Guangdong-Hong Kong-Macao Greater Bay Area was announced.

"The three newly appointed officials have been working hard with me at a time when the city faces unprecedented difficulties and (they) shouldered their responsibilities very well. They are the best candidates at the moment," Lam added.

Lee, 63, said he felt "really honored" after his appointment was announced. "I will fully support the chief executive to implement policies ... and assist her in fighting against the pandemic and boosting the city's economy," Lee said at the same briefing.

Tang, 55, said protecting Hong Kong and serving its people are his "lifelong commitments".

"In my new position, I will continue working with disciplinary services to crack down on crime ... including homegrown terrorism and national security-related cases," Tang said.

Tang also said he and his staff will spare no efforts to ensure that the upcoming elections for the Election Committee, Legislative Council and Chief Executive are conducted in a safe and stable environment.

Raymond Siu Chak-yee, the former deputy police commissioner, replaced Tang to lead the police force.

Siu, 55, said safeguarding national security, maintaining Hong Kong's stability and prosperity, and protecting the Hong Kong people will be his primary priorities.

"I want to express my thanks for the support and encouragement from the families of police officers and many Hong Kong residents as the police force faced unprecedented challenges over the past two years," Siu said.

Lam also thanked Cheung, 70, who joined the Hong Kong government in 1972, for his service and commitment to the people of Hong Kong for nearly half a century.