Hundreds of athletes and officials from around the world have already arrived for the Olympics, which open on July 23. Foreign spectators were ruled out in March, but the organizers had intended to allow stadiums and arenas to be around half capacity with local fans.
More than 3.5 million tickets have been purchased by people in Japan for the Olympics, which run through Aug. 8. Most of those tickets would have remained valid.
The plan was upended by a surge in infections in Japan this week, which prompted Prime Minister Yoshihide Suga to put Tokyo under a state of emergency starting Monday and lasting until Aug. 22, the fourth emergency period since the start of the pandemic.
Shortly after Mr. Suga declared the emergency on Thursday, representatives of Tokyo Olympic organizers, the International Olympic Committee and the Japanese government met and agreed to bar all spectators.
“We need to issue a message which is strong and easy to understand from the point of view of preventing further spread of infection,” said Seiko Hashimoto, the head of the Tokyo organizing committee.
Japan and some other countries in Asia that have been slow to roll out vaccinations are experiencing new waves of infection, exacerbated by the more contagious Delta variant. Infection rates remain low compared with some harder-hit countries, but the sudden increases are worrying governments and medical professionals.
On Thursday, the city of Tokyo reported 896 new infections, up 27% from a week earlier. Neighboring South Korea reported 1,275 new infections nationwide on Thursday, the highest number of daily cases since the start of the pandemic.
Opinion polls show the Japanese public remains concerned that the Olympics will contribute to the spread of infection. Tens of thousands of athletes, officials and others connected to the Games will travel to Japan for the event.
Organizers say most of those arriving in Japan will have been vaccinated, and strict limits on their movements have been imposed. They will also face frequent Covid-19 testing. Among those who arrived on Thursday was IOC President Thomas Bach, who will spend his first three days in his hotel room like others who come for the Games.
“I think we can only be very satisfied with the stricter measures having been established to protect everybody,” he said, speaking at the meeting via video link.
Still, some of the early arrivals for the Games are revealing weaknesses in Covid protocols. Three members of foreign delegations have tested positive for Covid-19, including one from Uganda who tested negative on arrival but positive a few days later after traveling to the city hosting the team’s training camp.
Highlighting the particular concern about the Games in Japan, even under the new state of emergency, events such as games in Japan’s professional baseball and soccer leagues will be allowed to continue with spectator levels at reduced capacity.
The ban on spectators at the Olympics has some exceptions for events that will be held at venues outside of the Tokyo region. The organizers have already asked people not to come and watch the marathon races that will take place in the city of Sapporo, on Japan’s northern island of Hokkaido.
Tokyo’s new state of emergency requires restaurants to close early and not serve alcohol. People will also be asked to avoid unnecessary trips, but as in previous cases public transport will keep operating and most stores will remain open.
In South Korea, authorities had been preparing to relax social-distancing measures, but outbreaks among people in their 20s and 30s prompted them to extend the restrictions until next week. Delta variant infections have doubled there over the past week.