Postponing the Tokyo 2020 Olympics will provide a welcome boost to the coronavirus-hit Japanese economy next year, a senior International Olympic Committee (IOC) official claimed on Thursday.

With tens of thousands dying around the world from the coronavirus, the IOC and Japan last month took the historic decision to delay the Olympics by one year, with an Opening Ceremony planned for July 23, 2021.

The pandemic has devastated the global economy as economists predict a second Great Depression, with $9 trillion wiped out and tens of millions of jobs lost.

Japan, the world's third-largest economy, is no exception, but IOC official John Coates told reporters holding the Games in 2021 could be a "very positive opportunity for an economic stimulus" that could "kickstart the economy again."

"I think there will be a lot of countries and cities around the world wishing for a similar opportunity," he said.

Economists at SMBC Nikko Securities have estimated postponing the Games would reduce Japan's GDP this year by some $6 billion -- to be recouped next year if the Olympics actually take place. Coates claimed Japanese Prime Minister Shinzo Abe "may well have had in mind that your country may be in a recession then and this would be an opportunity for a great economic stimulus".

In terms of the budget, organisers have already recognised there will be "massive" additional costs from the $12.6 billion the Games were supposed to cost -- shared between the Japanese government, Tokyo 2020 and the host city. Coates said they would use the postponement to look at ways of reducing those additional costs. Organisers would look at "what are the must-haves and what are the nice-to-haves," he pledged.

Moving the world's biggest sporting event is an unprecedented challenge that touches on every aspect of the organisation -- from hotels to venues and volunteers.

Organisers have stressed they are working towards a new Opening Ceremony on July 23, 2021 but Tokyo 2020 CEO Toshiro Muto has admitted uncertainty over the global impact of coronavirus. There is "no Plan B," Tokyo 2020 spokesman Masa Takaya told reporters at an online briefing on Tuesday.

Coates said by choosing to move the Games by a whole year -- rather than hold them in the Spring -- they had given themselves "as much time as possible," stressing that athletes' health would be the guiding principle.