Monthly pyrotechnic displays along the harbourfront could make it easier for people to plan trips to Hong Kong and entice tourists to stay in the city for another night, Financial Secretary Paul Chan said on Thursday.

A caller to a phone-in programme on Chan's latest budget said the plan to use fireworks and drone displays to regularly create "enchanting moments" for visitors and locals might lack an element of surprise.

"You could consider setting themes for the displays, for example, basing them on the four seasons. Other than having themes, they should be done across various departments and with other projects," said the caller surnamed Wong.

"The frequency of such shows should be once every season. They don't have to be too often, so that you have more budget for a bigger display," she suggested.

In response, Chan said having monthly shows could provide convenience for tourists when planning their itineraries, and that it's up to the Tourism Board to come up with the details of the shows.

"It gives them [visitors] more places to visit and makes them stay one more night... When the show is held along with other events, it can enhance the overall attractiveness and experience," Chan said.

“[Having a regular schedule] can allow vendors to plan for their business and launch special products," he added.

On another caller's comment that high costs for tourists are pushing people away, Chan said Hong Kong is never "competing to be cheap", adding that it is important to improve service quality.

Another issue discussed during the phone-in programme was Wednesday's almost 32 percent hike in tobacco tax.

Chan warned that the duty will continue to rise in future to meet the level recommended by the World Health Organisation.

"We haven't reached the 75 percent [recommended] standard, so there will be further increases. We hope to cut smoking rates [by raising taxes]. In fact, since we raised taxes last year, there's been a decline in our smoking rates," he said.

Separately, Chan said the government has no plans to raise the age threshold for the HK$2 transport subsidy scheme from 60 to 65.

The administration says, however, that it is planning to review the scheme.