Chief Executive John Lee on Monday said the enactment of legislation under Article 23 of the Basic Law gave Hong Kong strong protection against threats to national security.

Speaking at the opening ceremony of the National Security Education Day, Lee warned the SAR must remain vigilant.

"The threat of an attack from hostile forces will continue. Like a virus, it doesn't stop just because we've been vaccinated. The virus won't disappear automatically," said Lee, who also chairs the Committee on Safeguarding National Security.

"Similarly, even after the implementation of national security laws, activities that endanger national security will continue to attack us like viruses. So, we cannot forget about the pain after the wounds have healed."

The CE set out four ways in which his administration would protect national security, including explaining the national security laws, strengthening internal systems, preventing and punishing illegal acts, and enhancing education.

Meanwhile, the director of the Liaison Office, Zheng Yanxiong, said Hong Kong could focus on developing the economy with national security laws in place.

"’One Country, Two Systems’ will remain unchanged for a long time and has become a broad social consensus. The common law system is still effective, the three major centres are still significant, horse racing and stock trading are still vibrant, and the Pearl of the Orient remains romantic," he said.

Zheng added Hongkongers should unite to guard against external forces who spread rumours and create a better future for the SAR.