Health minister Lo Chung-mau has played down the likelihood of Hong Kong quickly doing away with quarantine hotels and moving to seven days of health monitoring instead.

Speaking on two radio programmes on Saturday, he said the latest move to three days of hotel quarantine from seven could see arrival numbers increase by 60 to 80 percent, as more quarantine hotel rooms would now be available.

But he told reporters after the show that dropping hotel quarantine - and moving to a so-called Zero plus Seven system - would ultimately depend on the nature of the Covid pandemic and any data collected.

He said it was only responsible for the authorities to take a gradual approach towards adjusting entry requirements.

"I can't promise. [It] depends on the Covid situation. Everyone hopes to have more resumption of travel and economic activities, but we have to look at the Covid situation. And we have to remember that the virus is continuing to mutate and the pandemic is continuing to evolve. Even WHO and many experts have warned that the pandemic is not over yet," he said.

"To say hastily that we will relax everything and go to a zero-quarantine measure will be not practical."

Meanwhile, Professor Lo said the increase in the daily Covid tally had been slowing down, though he urged people not to let their guard down.

He said people undergoing medical surveillance, with an amber code on their LeaveHomeSafe app, should not go to the homes of family members or friends, or take part in group activities where people don't wear masks.

He said while there was no checking of vaccine passes at private premises, he hoped everyone would abide by the law.

But he said the administration would review, depending on the Covid situation, whether current rules could be relaxed so those with amber codes could go to places like hair salons and exhibition venues, where people didn't need to remove their masks.

Separately, the official called on parents of children aged between six months and three years old to get jabbed, saying the vaccination rate of those in this age group wasn't ideal.

He said parents shouldn't wait for the BioNTech jab to become available for their children.

He said the government was handling contract issues with the manufacturer but that the child version of the vaccine was in tight supply.

Currently, children below five years old can only receive the Sinovac jab.