Coronavirus: Tokyo Olympic Games postponement is about 'saving lives' - Thomas Bach

International Olympic Committee chief Thomas Bach says he and Japanese Prime Minister Shinzo Abe have not discussed the cost of postponing the Tokyo 2020 Olympic Games until 2021, due to the coronavirus, as it is a "matter of saving lives".

The July 24-August 9 event will be rescheduled for the summer of 2021 at the latest, as proof of victory over the coronavirus, the IOC and Tokyo 2020 organisers said in a joint statement, after an agreement between Bach and Abe.

"This is about protecting lives," Bach told a conference call on Tuesday, after his call with Abe triggered the first postponement of the Olympic Games in their 124-year history.

The precise dates for the new Games have not yet been determined.

"About two hours after my phone call, I cannot give you a definite answer," Bach said.

"These are the reasons why we had decided we need at least four weeks to assess all these questions," Bach added on a phone call with journalists. "These are not the only ones."

On Sunday, the IOC, who had long insisted the Games would go ahead as planned, said it was considering the option of postponement with a four-week consultation period.

But mounting opposition from athletes and teams over participating in Tokyo this year, due to huge problems preparing themselves, piled more pressure on the IOC.

Bach said alarming figures about the spread of the virus in recent days had left little choice in the matter.

"We agreed, given these circumstances, that the Games must be rescheduled to a later date beyond 2020, but not later than summer 2021," he said.

Coronavirus: Tokyo Olympic Games postponement is about 'saving lives' - Thomas Bach

The IOC and organisers are now faced with a massive undertaking of rescheduling the Games that has a multitude of moving parts with 33 sports involved and an additional price tag to the $US12 billion ($A20 billion) already spent by Tokyo for the Olympics.

Bach said the IOC's coordination commission had already started work on this project and would work towards determining new dates.

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, and the logistical headaches and financial losses involved, a poll indicated that about 70 percent of Japanese agreed with the delay.