Justice Secretary Paul Lam on Sunday said the authorities hope to enact Basic Law Article 23 national security legislation this year, or at the latest by the end of next year.

Speaking to reporters before going to Beijing for an official visit, Lam said the government has a timetable, and the issue might be discussed when he meets mainland officials in the capital.

"We hope to complete it within this year. But at the latest we hope to fulfil our constitutional duty next year," he said.

"I will visit different ministries during my trip to Beijing, and will look into various issues. Of course, things that involve our constitutional duty, including Article 23, are things that greatly concern the central government and the SAR administration. So it is reasonable and natural that such matters may be discussed."

The justice minister said his five-day trip to Beijing will include visits and meetings with people from the Legislative Affairs Commission, Basic Law Committee, Ministry of Justice, as well as the Hong Kong and Macau Affairs Office.

Lam said he looks forward to discussing how the legal systems on the two sides of the border can work together.