An anti-tobacco advocate on Wednesday hailed the work of Hong Kong in bringing down the city's smoking rate over the past 40 years, but said more needs to be done to further deter people from lighting up.

Dr Judith Mackay, director of the Asian Consultancy on Tobacco Control, told RTHK's Hong Kong Today programme that the city had performed "remarkably well", passing a slew of legislation and raising the tobacco tax.

But Mackay said the government needs to bring in further measures as there are still hundreds of thousands of smokers in the territory.

She threw her support behind a proposal by the government to continuously raise the city’s legal smoking age, saying studies show the average age to take up the habit is under 20, when youngsters' brains are still not fully developed.

"So if we can prevent people from starting smoking until they're 23 or 24, then they're most unlikely to start," Mackay said.

The expert added that raising the tobacco tax is also crucial in discouraging youngsters to smoke.

"They just simply can't afford expensive cigarettes. It's as simple as that. So it's not health education in schools, it's actually a fiscal measure that really helps them stop. And we haven't had a tax increase, inexplicably, we haven't had a tax increase since 2014," Mackay said.

Health minister Lo Chung-mau said on Tuesday that the government is considering completely banning future generations from buying tobacco products.

Lo said the city's smoking rate is currently at 9.5 percent – down from 23 percent in the early 1980s.