“We must achieve near to zero, or sustain a low number of, confirmed cases, and very importantly, no unlinked cases.

“In the eyes of mainland authorities, they will look into whether Hong Kong, in their classification, is still a high- or medium- risk area.”

Mainland quarantine exemptions would remain a distant prospect for as long as Hong Kong still presented Covid-19 risks, Nip said, but added: “We are still exploring the possibilities to allow vaccinated residents to return to the mainland without the need of quarantine.”

Lifted as part of the government’s Return2HK scheme, mandatory 14-day quarantine will not apply on a widespread basis for the first time in more than a year.

It allows Hong Kong residents to come back from anywhere on the mainland without spending any time in coronavirus-related confinement.

The programme, which launched last November, originally applied only to those arriving from Guangdong province and Macau.

Those taking part in the extended scheme must secure a place online before coming back, with the booking system launching on Tuesday. Residents will be able to schedule their quarantine-free return for between April 29 and May 16.

Adults can also book for three other family members, including children aged under 18 and the elderly.

Returnees need to undergo coronavirus screening through any mainland-authorised institution within three days of their return.

The quotas at land borders restricting the number of people who could come back per day under the Return2HK scheme would remain the same because the system was currently running with spare capacity, Nip explained.

The daily quotas for crossing via the Shenzhen Bay Port and the Hong Kong-Zhuhai-Macau Bridge will remain at 3,000 and 2,000 per respectively.

04:04

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Residents taking part in the scheme must carry a hard copy of their negative test result for crossing the border and also upload a digital version to a Department of Health system when filling in an online declaration beforehand.

Those who have received a green QR code will be allowed to cross the border without quarantine. Returnees will also have to take another two mandatory tests on the 2nd and 12th day after their arrival in Hong Kong.

For the first time, residents will be allowed to travel under the Return2HK scheme through Hong Kong International Airport, for which there will be a daily quota of 1,000.

“For these residents, they need to do a virus test and wait for the results at the airport designated waiting area. People are also required to do another mandatory testing on the 12th day after arrival in Hong Kong,” Nip said.

The secretary for the civil service said the coronavirus situation on the mainland had been under control for a certain period of time.

Residents returning to the city must also prove they have not visited any places outside the mainland, or middle- and high-risk areas within the mainland, 14 days before their return.

“If there is any outbreak in some mainland areas, the National Health Commission will list those places as medium- or high-risk areas, thus the Hongkongers who have been to those places will fail to meet the requirements for travelling back to Hong Kong,” Nip said.

As of Sunday, two parts of west Yunnan were classified as high risk, while another area, in the same province, was listed as medium risk, according to the commission.