Secretary for Security Chris Tang on Wednesday said his visit to Beijing has yielded fruitful gains, including meaningful talks with mainland officials about national security and cross-border crimes.

During his trip, Tang met with Chen Wenqing, party secretary of the Central Political and Legal Affairs Commission; Wang Xiaohong, state councillor and minister of public security; and the head of the Hong Kong and Macau Affairs Office, Xia Baolong.

"[The officials] urged us to become the guardian of national security, enforcer of the national security law, and the protectors of Hong Kong's prosperity and stability. They also reminded us that there are still national security threats in the SAR," he told reporters in Beijing.

Tang said the three top officials acknowledged the work of Hong Kong's disciplined forces, and called on the SAR to guard against national security threats.

On Article 23 national security legislation, the security minister said officials are doing preparatory work by studying local and overseas court cases and the experience from the 2019 protests.