'Can't believe it': Tokyo 2020 Olympics called off in stunning 124-year first

Japan and the Olympics movement have decided to delay this year's Tokyo Games into 2021 as the coronavirus crisis obliterated the world's last major imminent sporting event.

It was the first time in the Olympics' 124-year history that they had been postponed, though they were cancelled outright several times during the two 20th century World Wars.

‘NO JOKE’: Olympics rocked by gold medallist's positive test

After a call with International Olympic Committee (IOC) president Thomas Bach, Japan's Prime Minister Shinzo Abe said the July 24-August 9 event would be rescheduled for the summer of 2021 at the latest as proof of victory over the coronavirus.

"We asked President Bach to consider postponement of about one year to make it possible for athletes to play in the best condition, and to make the event a safe and secure one for spectators," Abe said.

"President Bach said he is in agreement 100 per cent."

There was no immediate word from the IOC, though its executives were due to meet later on Tuesday.

Pressure on the IOC and its powerful president Bach had been accelerating fast in recent days, with Canada and Australia refusing to participate if the Games went ahead in the summer.

Athletes react to Olympics delay

Athletes wholeheartedly endorsed the delay, given health risks and disruption to their training as gyms, stadia and swimming pools shut down around the world.

"To be honest, I'm left reeling and feeling a little lost. But the goal posts haven't disappeared - just shifted. It's time to recalibrate and fire up for the next challenge," said Australia's two-time Olympic champion swimmer, Cate Campbell.

Some athletes were sad but relieved on Tuesday after weeks of worrying and struggling to train as the world headed into virtual lockdown from the disease that has claimed more than 16,500 lives.

"I compete in a little bike race, which is nothing compared to what is going on in the world right now," American Olympic BMX champion Connor Fields said.

"No sport is more important if it means more people might potentially die from this."

The coronavirus outbreak has raged around the world since early this year, infecting nearly 380,000 people and wrecking sports events from the soccer Euros to Formula One.

Postponement is a massive logistical headache for hosts Japan, which has pumped in more than $US12 billion ($A20 billion) of investment.

But a poll showed about 70 per cent of the Japanese agree with a delay.

Tokyo Governor Yuriko Koike told reporters the delayed Games would still be branded "Tokyo 2020".