The unimpeded spread of the coronavirus has forced the Tokyo Olympics to be postponed until next year, bringing relief to thousands of athletes who were fretting over how to train as the world headed into lockdown.

Japan’s Prime Minister Shinzo Abe and International Olympic Committee president Thomas Bach agreed to hold the Games by next northern summer at the latest, making it the first such delay in its 124-year modern history.

Their decision came a day after the World Health Organisation warned the global pandemic had been “accelerating” and with decisive action its trajectory could be altered.

Though a huge blow to Japan, which has invested $US12 billion ($A20 billion) in the run-up, the Olympics’ return in 2021 will serve as a celebration of triumph over the coronavirus, a statement announcing the decision read. 

The IOC conceded on Wednesday morning (Australian time) the coronavirus not only presented an “unprecedented challenge for mankind” but an unprecedented challenge for the Games.

With some athletes and sporting bodies angry that a seemingly inevitable decision had taken so long, others took to social media to express their relief at the announcement.

Training would continue for Jamaican Olympian, Michael Gunning, who posted a “home workout” video showing how he will get through “these challenging times”.

COVID-19 had presented health risks and disruption to many athletes’ training as gyms, stadia and swimming pools shut down around the world.

https://twitter.com/MichaelGunning1/status/1242512206958415873

The delay also came 122 days before the planned opening ceremony at Japan’s newly-built National Stadium, which was to usher in the 16-day carnival of sport featuring 11,000 athletes from 206 nations and territories.

The Olympic flame, already lit at Olympia in Greece and carried around Japan in a now-cancelled torch relay, would stay in the host nation until then as a symbol of hope.

“This Olympic flame will be the light at the end of this tunnel,” IOC president Mr Bach said.

Australian double Olympic champion swimmer Cate Campbell said she was reeling but ready for the new challenge.

“The goalposts haven’t disappeared – just shifted,” she said, after Australia had said it would not go to Tokyo 2020 if it went ahead.

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

Despite their disappointment, not to mention the logistical headaches and financial losses coming, a poll indicated that about 70 per cent of Japanese agreed with a delay.

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

In a crowded sporting calendar, which will be making up for this year’s cancellations, World Athletics said it was willing to move its world championships, scheduled for August 6-15, 2021, in Oregon, to clear a path for the Olympics.

The Athletics Association said a poll of more than 4000 track and field competitors had indicated that 78 per cent had wanted the Games to be delayed.

It was not yet clear whether the athletes who had already secured spots in Tokyo this summer – more than half of those due to compete – would need to qualify again.

Postponing the Olympics is also a heavy blow that is almost certain to push Japan’s persistently weak economy, the world’s third-largest, into recession.

Though it was the first Olympics’ postponement, they were cancelled outright three times during the two 20th century World Wars. Major Cold War boycotts also disrupted the Moscow and Los Angeles Games in 1980 and 1984.

-with AAP