Chinese organizers have confirmed participants in next year's Winter Olympics will be strictly isolated from the general population and could face expulsion for violating COVID-19 restrictions.

Vice mayor and Beijing 2022 organizing committee official Zhang Jiandong told reporters Wednesday that those taking part in the games beginning Feb. 4 must remain in a "closed loop" for training, competing, transport, dining and accommodation.

A strict Olympic bubble has long been on the books, but Beijing has now made it official in keeping with its zero tolerance approach to the pandemic. Athletes and other participants will also be tested regularly for the coronavirus before and during the Games. Family, spectators and sponsors from outside the country will not be allowed to attend.

"All participants of the Games and our Chinese staff and volunteers will implement the same policy," Zhang said. "They will be strictly separated from the external society.

"Those who do not comply with the epidemic prevention regulations may face severe consequences such as warning, temporary or permanent cancellation of registration, temporary or permanent disqualification or expulsion from the competition, and other punishment."

All participants must have been fully vaccinated at least 14 days prior to their departure for China.

China has enforced strict rules on mask wearing, quarantines and contact tracing that have largely succeeded in eliminating the local transmission of COVID-19, but imported cases and domestic infections continue to appear in daily reports.

"Indeed, epidemic prevention and control is the biggest challenge for us to host the Winter Olympic Games," Zhang told a news conference.

Wednesday marked 100 days until the Beijing Games. Organizers have held test events featuring international athletes at Olympic venues under strict conditions.

Japan imposed restrictive rules and an Olympic bubble during the July 23-Aug. 8 Summer Games in Tokyo, which had been postponed by 12 months because of the pandemic.