HONG KONG — Hong Kong leader Carrie Lam says authorities would reclassify countries into high, medium and low-risk, and update quarantine requirements to favor vaccinated travelers as it seeks to prevent imported coronavirus infections from leaking into the community.

Under the new measures announced Monday, only vaccinated Hong Kong residents will be able to return to Hong Kong from countries deemed high-risk. For medium-risk countries, only Hong Kong residents and vaccinated non-residents can return to the city.

All arrivals must present a negative coronavirus test result taken within the 72 hours before they board their flight to Hong Kong.

Authorities also said civil servants must get vaccinated or get regular coronavirus tests at their own expense.

Staff in quarantine hotels and at the airports, as well as employees at schools and homes for the elderly and the disabled were also ordered to get vaccinated or pay for regular testing in the future.

Certain restaurant workers who are unvaccinated will also need to be tested every seven days instead of every 14 days.