Hong Kong must be on constant guard against emerging national security threats, Chief Executive John Lee has warned, saying rapid and incessant advances in artificial intelligence could present completely new challenges to the territory.

The CE said in his first three years in office, Hong Kong has so far been successful in safeguarding national security against "foreseeable" threats.

The territory’s defences have recently been bolstered by new subsidiary legislation to the SAR’s home-grown national security law, with authorities saying the newly-implemented clauses better enable them to address threats amid a complicated geopolitical situation.

However, Lee said constant advances in technology present a stiff challenge.

"For example, no one knows how artificial intelligence will affect espionage activities, so we have to adapt to the situation," he said.

"We cannot take things lightly and must have a bottom-line mentality. At a time of rapid and profound change – especially in terms of technological development – we must keep a close watch on new vulnerabilities in terms of national security."

Lee also underscored the need to strengthen intelligence gathering and training to better enable authorities to counter emerging threats.

The chief executive also spoke about the upcoming Legislative Council elections in December, stressing that anyone eligible is free to challenge for a seat – so long as they put Hong Kong’s interests first.

He said the city must continue to adhere to the "patriots governing Hong Kong" principle.

"No one anywhere has ever said ‘I’m running for office because I’m a traitor.' That’s not an election platform I’ve ever heard of," Lee said.

"It is very reasonable that anyone who would betray the country and sell out Hong Kong’s interests should not be involved in governing Hong Kong."

But for those who prioritise the interests of the country and the SAR, he added, the sky is the limit.