Olympics chief Thomas Bach pledged Wednesday "not to bring any risk" to Japan with the Games, seeking to reassure a sceptical public as virus cases surge just over a week before Tokyo 2020 begins.

Fans have been banned from Olympic events in the capital, which is under emergency restrictions to curb rising infection numbers that on Wednesday hit highs not seen since January.

As more athletes arrive in Japan and move into the Olympic Village, International Olympic Committee chief Bach promised a safe summer Games.

"We are making all our efforts and the Japanese people have all our commitment to contribute in the best way to fight this virus and not to bring any risk to the Japanese people," Bach told reporters after meeting Prime Minister Yoshihide Suga.

Bach said "85 percent of all the residents in the Olympic Village and almost 100 percent of the IOC members and staff coming here to Tokyo arrive vaccinated.

"This is why I'd like to humbly ask the Japanese people to warmly welcome the athletes from all around the world who have overcome, like the Japanese people, so many challenges."

IOC president Thomas Bach (C) bows to Japan's Prime Minister Yoshihide Suga (R)
IOC president Thomas Bach (C) bows to Japan's Prime Minister Yoshihide Suga (R) POOL / KIMIMASA MAYAMA

Japan has seen a less severe Covid-19 outbreak than many other countries, with around 15,000 deaths overall, but experts warn another wave driven by more infectious variants could stretch medical facilities.

Around 20 percent of the population are fully vaccinated, and Tokyo's emergency measures, mainly limiting alcohol sales and restaurant opening hours, will be in place throughout the Games.

On Wednesday there were 1,149 new cases recorded in Tokyo, the highest since January 22.

In opinion polls, the Japanese public have consistently expressed apprehension about Tokyo 2020, which was postponed by a year due to the pandemic and will finally open on July 23.

Organisers announced the decision to ban spectators from all but a tiny number of Olympic events last week, following repeated warnings from experts about the risk of crowds gathering as infections rise.

Olympic officials stressed that just a tiny percentage of the people coming into Japan for the event had tested positive for the virus
Olympic officials stressed that just a tiny percentage of the people coming into Japan for the event had tested positive for the virus AFP / Philip FONG

In an exchange with major global press agencies later on Wednesday, Bach said his team had strived to maintain a confident stance after Tokyo 2020 was postponed in March last year.

"In these 15 months, we had doubts every day. This was a situation of high uncertainty," he said.

"Quite honestly, it was way, way more complex than we thought it would be when we agreed on this postponement."

But by projecting confidence and taking decisions seriously, the IOC kept other parties on side, from athletes to sports federations and local authorities, Bach said.

"Only because they all stayed on board, we can be here now, nine days before the opening of the Games."

The US softball team moved into the Olympic Village on Wednesday, local media said, the day after the compound opened without any of the welcome ceremonies or media opportunities often seen at the Games.

But the arrival of the Refugee Olympic team was delayed after an official tested positive in Doha, the IOC said. All the team's athletes tested negative.

While in Japan, athletes will face strict virus rules and are banned from eating at local restaurants or interacting with the public.

Olympic officials on Wednesday stressed that a tiny percentage of the people coming into Japan for the event had tested positive for the virus.

Of the more than 8,000 people who arrived between July 1 and 13, three tested positive after arrival and were isolated, with their close contacts also "subject to the relevant quarantine measures", the IOC said.

While Tokyo 2020 will not have the same celebratory atmosphere of previous Olympics, Bach said audio of crowds at past Games will be played to encourage athletes, while TV audiences worldwide can contribute to a virtual "clapping" map.

Bach is scheduled to visit Hiroshima on Friday on a visit he denied was politically motivated, saying it would show the IOC's "commitment to peace" on the first day of the Olympic truce.

The truce -- adopted by the United Nations -- aims to ensure a halt to all hostilities, allowing the safe passage and participation of athletes and spectators for the Games.