International Olympic Committee President Thomas Bach says he understands why the rescheduled Tokyo 2020 Games would have to be cancelled if it cannot take place next summer.

Local organisers have said they have no back-up plan after the event was postponed by a year because of the coronavirus crisis.

“You cannot forever employ 3,000 to 5,000 people in an organising committee,” Bach told BBC Sport. “You cannot have the athletes being in uncertainty.”

“You cannot forever employ 3,000 to 5,000 people in an organising committee,” Bach told BBC Sport. “You cannot have the athletes being in uncertainty.”

Bach said he hoped the first-ever postponed Games, which are due to take place from 23 July to 8 August 2021, could prove “unique” and send “a message of solidarity among the entire world, coming for the first time together again, and celebrating the triumph over coronavirus”.

“There is no blueprint for it so we have to reinvent the wheel day by day. It’s very challenging and at the same time fascinating.”

Japan’s Prime Minister Shinzo Abe has admitted it may be “difficult” to stage the Games if the country does not successfully contain the virus, and the head of the Japan Medical Association has suggested it depends on finding a vaccine.

When asked directly if he agreed, Bach said: “For this question, we are relying on the advice of the World Health Organisation.

“We have established one principle: to organise these Games in a safe environment for all the participants. Nobody knows what the world will look like in one year, in two months.

“So we have to rely on [experts] and then take the appropriate decision at the appropriate time based on this advice.”

The 2022 Beijing Winter Olympics are due to take place in China just six months after the Tokyo Games, and Bach said that Prime Minister Abe had made it clear to him that, as far as Japan was concerned, next summer was “the last option”.