The call was made as Japan witnesses a spike in virus cases, triggered by mutated variants, as well as a shortage of hospital beds and medical staff in some areas under a state of emergency.
With two months before the Olympics, there has been increased public concern about the possible effect of the sporting event on the country's healthcare system because an estimated 10,000 medical staff will be needed for the event, according to the organisers.
In the meantime, the International Olympic Committee and Japanese organisers will later on Friday conclude a three-day virtual meeting held to deliberate on arrangements for the Olympics, scheduled to open on 23 July after a one-year delay.
The Olympics and Paralympics, which are expected to gather 15,000 athletes from across the world, have had several teams abandon plans to train in Japan ahead of the games due to safety concerns. Some 59 municipalities across Japan have cancelled plans to host athletes for pre-Olympic training camps and cultural exchanges.