Athletes participating in the Beijing 2022 Winter Olympics will have to take daily COVID-19 tests and remain in a closed loop, including travel between games venues, the Games organizers said in guidelines released Monday.

China, where measures against COVID-19 are among the world's strictest, has already said international spectators will not be allowed to enter the country for the Games that will run from Feb. 4 to Feb. 20.

China has all but shut its borders to international travelers, with the number of international flights drastically reduced from pre-COVID-19 levels, and games organizers said Monday that domestic and foreign airlines will be encouraged to operate temporary flights available only to participants.

Games participants will need to be tested for COVID-19 before arrival, and athletes and team officials must be vaccinated to avoid 21 days in quarantine, with some exceptions for medical reasons granted on a case-by-case basis.

"We want everyone at the Games to be safe, that's why we're asking all participants to follow these guidelines," IOC Olympic Games Executive Director Christophe Dubi said in a statement.

"Keeping everyone healthy will ensure the focus remains on the very fundamentals of the Olympic and Paralympic Games – the athletes and the sport."

Organizers added that the closed-loop system has been designed to keep competitors safe by reducing unnecessary interactions.

Competitors will also be encouraged to wear masks and avoid spaces that are enclosed, crowded or involve close contact while every organization taking part in the Games will be asked to nominate COVID-19 Liaison Officers.

Vaccination is not mandatory for the Beijing Games but some national Olympic committees, including that of the United States and Canada, are requiring team members to be vaccinated.