Hong Kong's justice chief has stressed that educating the public on national security is an ongoing effort, calling on people to stay vigilant against possible threats.

In the run-up to the city's National Security Education Day on April 15, Secretary for Justice Paul Lam told local newspaper Sing Tao Daily that the push to raise public awareness should not be limited to certain days.

For example, he said, one should not treat one's spouse well only on Valentine's Day, adding that national security education should similarly be an everyday thing.

Lam also warned that national security risks might still exist even though Hong Kong now has a very stable environment.

One of six officials recently sanctioned by the United States, Lam said Washington's move might encourage more people to take part in work to safeguard national security.

He said the punitive actions would not affect him and that none of the officials placed on Washington's list left their job as a result of the sanctions.

While no one would be happy to be sanctioned, Lam said, it did not mean that they had to be agitated and upset over it.