Under current rules, everyone intending to fly into Hong Kong must show a negative Covid test result obtained within 72 hours of departure.
But from Christmas Eve, people will have to show a test taken within 48 hours.
Meanwhile, the government says an airline’s flights into Hong Kong on a particular route will be suspended for two weeks if, within a week, four or more passengers via that route are confirmed with Covid.
But the administration has eased a requirement for people coming from countries under the most stringent surveillance to spend time in a government quarantine camp.
At present, people flying in from places such as South Africa and the United States must spend a week in the Penny’s Bay camp.
But from Tuesday, that will be cut to four days. From the same day, the requirement will also apply to arrivals from Britain.
Officials said the change is possible because so far, all imported Omicron cases were detected within three days of arrival, and the government can therefore make better use of the quarantine facilities at the Penny’s Bay centre.
The government also said it’ll classify Peru as a high risk country from Thursday in light of Omicron cases found in the country.
Only fully-vaccinated Hong Kong residents will be allowed to enter the SAR if they’ve been in Peru in the previous 21 days. They will be required to spend 21 days in quarantine hotel.