China's State Council Information Office released a white paper on Tuesday titled "Hong Kong: Safeguarding China's National Security Under the Framework of One Country, Two Systems", comprehensively reviewing the practice and outlining the way ahead for ensuring security and stability in the Hong Kong Special Administrative Region.

The document was released a day after the HKSAR's High Court sentenced former media mogul Jimmy Lai Chee-ying to 20 years in prison, following his December convictions for activities that endangered national security — a move that was immediately endorsed by the central government and the city's leadership.

It systematically details the necessity, legal foundations and achievements of national security work in the HKSAR, emphasizing that safeguarding national sovereignty, security and development interests is the "highest principle" in the implementation of "one country, two systems".

According to the white paper, the central government, in the face of "turbulent and changing circumstances" in Hong Kong, has upheld the overall national security concept and exercised its comprehensive jurisdiction in accordance with China's Constitution and the Basic Law of the HKSAR.

The document also notes that, regardless of changes in the international landscape, the central government will always lend its full support to Hong Kong in building a high-standard security environment, preventing and defusing major risks and hidden dangers and extensively expanding its global reach.

A spokesperson for the State Council's Hong Kong and Macao Affairs Office said that the document provides a thorough review of Hong Kong's national security practices, reaffirms the central government's staunch backing for the city and consolidates essential insights and experiences for upholding national security under "one country, two systems".

The spokesperson reiterated that fostering a Hong Kong that is safe, while free, prosperous, open and vibrant, is in line with core national interests, benefits the welfare of its residents and serves the needs of investors.

The Liaison Office of the Central People's Government in the HKSAR called the white paper a "new starting point" for deepening the city's national security work, saying that enhanced security will continue to support Hong Kong's high-quality growth.

A spokesperson for the Office for Safeguarding National Security of the Central People's Government in the HKSAR said that measures implemented to safeguard national security constitute a vital part of the bedrock for the sustained practice of "one country, two systems".

Hong Kong Chief Executive John Lee Ka-chiu said the white paper offers practical guidance for the HKSAR and "comes at just the right time", and he urged all sectors in Hong Kong to study and grasp its essence and direction.