A panel of public health experts has found issues over anti-infection measures at the Tokyo Olympic and Paralympic Village for athletes and staff.
Panel members discussed the issues at a meeting on Friday after visiting the village.
They cited the need for enough space for self-isolation in case infections occur.
They also called for measures to shorten waiting times at the village's clinic and to avoid crowding in dining halls.
The members also discussed potential infection risks at public viewing and other event sites to be set up for the games.
Saito Tomoya from the National Institute of Infectious Diseases said such sites may lead to more foot traffic and infections.
But Saito said risks can be reduced by limiting numbers of visitors and creating rules on eating and drinking.
He warned that without such venues, people may gather at homes or sports bars and end up putting themselves at higher risk of infection.