The government on Wednesday said it has demanded Japan authorities withdraw a decision to restrict flights from Hong Kong to only four of its airports, while assuring holidaymakers that they will still be able to fly home from Japan.

Tokyo earlier announced that from Friday, passenger flights to and from Hong Kong, Macau and the mainland can only land in Tokyo, Osaka and Nagoya, while arrivals will be given Covid tests amid concerns about infections and easing pandemic curbs on the mainland.

SAR officials said airlines will not be allowed to put on any additional flights to Japan from Hong Kong.

But Chief Executive John Lee told reporters on Wednesday that the government has requested Japan authorities to scrap the move, adding that officials have been in talks with the Japanese authorities on how to help stranded passengers.

"We have indicated to the Japanese government that we are disappointed with the arrangement because we think that Hong Kong people and Hong Kong flights should be allowed to use not just its four airports. And we will also approach the Consul-General of Japan in Hong Kong to relay that message," he told a press conference.

"Besides that, our ETO [Economic and Trade Office] in Tokyo is trying to help anybody who needs assistance. We will stand by for any extra request that Hong Kong citizens may have."

Separately, transport minister Lam Sai-hung said the Japanese authorities have told Hong Kong that passengers can still be brought home from other Japanese airports such as those in Sapporo, Fukuoka and Okinawa, even after the restrictions come into force on Friday.

Officials also said they have been in touch with local airlines and have been told they will try their best to bring home travellers affected by Tokyo's new policy.

Yuen Chun-ning, the chairman of travel agency WWPKG Holdings Company, told RTHK that at least 50,000 people who were planning to go to Japan in January will be affected by the move.

"There are around a dozen flights for Sapporo every week and 10 flights to Fukuoka. There are tens of thousands of seats in total and they are fully booked during the Lunar New Year in January," he said.

Fanny Yeung, the executive director of the Travel Industry Council, said she expects at least 1,000 visitors to call off their trips in the coming week alone because of the new arrangement.

"Just talking about today, one-third of the visitors to Japan... they cancelled the trip because they cannot be certain about the return journey. And then we expect in the coming week, at least over 1,000 visitors will cancel their trip to Japan because of this measure," she said.

Hong Kong Airlines announced that it will cancel flights to Hokkaido and Okinawa from Friday, saying it will arrange full refund and flights to bring back affected passengers.

Another airline, Peach Aviation, said it will cancel all flights between Hong Kong and Osaka from January 20 to February 1, adding that passengers can choose to apply for refund or take an alternative flight.