Tokyo Olympics organising committee chief Toshiro Muto has not ruled out cancelling the Games at the last minute should there be a surge in coronavirus cases.

Officials announced a further nine positive cases among those linked to the Games on Tuesday, taking the overall number of people infected since the start of July to 71.

That total includes South Africa's men's footballers Thabiso Monyane and Kamohelo Mahlatsi testing positive while inside the athletes' village over the weekend.

A number of other athletes have been forced to isolate after coming into close contact with an individual that has contracted the disease.

With just three days to go until the global sporting event's opening ceremony, and with the first events starting as soon as Wednesday, director general Muto will continue monitoring infection levels in the hope they do not spiral out of control.

"We can't predict what will happen with the number of coronavirus cases. So we will continue discussions if there is a spike in cases," he said at a news conference.

"We have agreed that based on the coronavirus situation, we will convene five-party talks again.

"At this point, the coronavirus cases may rise or fall, so we will think about what we should do when the situation arises."

Around 11,000 athletes from 205 national Olympic committees are expected to stay at the Olympic Village over the next three weeks.

The 2020 Games, delayed by a year due to the global health pandemic, will be held mostly without spectators due to a state of emergency being declared in Tokyo.

The number of new coronavirus cases in the Japanese capital topped 1,000 for five days running before dropping to 727 on Monday.

Amid concerns from the wider population over the Games going ahead, Japan's chef de mission Tsuyoshi Fukui insisted a number of safety measures are in place to stop the virus spreading.

"Under these circumstances, we must admit that COVID-19 is not subsiding," Fukui said on Tuesday. "We have to pay tribute to many people that enabled us to start the Games.

"We will give our utmost efforts so that the athletes can do their best. We will, as Team Japan, never forget the sense of appreciation. As of Monday night, the Japanese athletes staying at the Athletes' Village is 236.

"We have seen more and more athletes from other nations enter the Village, but there are rigorous COVID-19 countermeasures enforced and so far, there has been no major issues.

"Including myself, athletes and other members are taking antigen tests every day, as well as using an app to monitor our health situations.

"Every time we enter the Athletes' Village, our temperatures are checked, and we disinfect our hands.

"In the dining hall, each seat is separated by acrylic boards. Also, everyone is also wearing face masks – so we have a strong sense that rigorous measures against the spread of COVID-19 are in place by the organising committee."

He added: "There are various opinions regarding the Games and we are aware of that. We would like to earnestly listen to and take these opinions into account, but at the same time the mission of the Japanese delegations is to establish an environment where an athlete could focus on sports.

"So through sports we want to deliver hope and bravery and to make sure that each athlete can do their best in their performance."