Some 8.8 million tickets for the Games have been sold worldwide. In line with IOC regulations, the host country can sell 75 percent of tickets domestically, with the remaining 25 percent sold overseas. Some 4.48 million tickets have been sold to Japanese nationals.

Ticket prices for the Tokyo Olympics opening ceremony range from 12,000 yen to 300,000 yen. For a specific event, such as the men's 100 meters final, prices are from 5,800 yen to 130,000 yen. Total revenue from ticket sales for the Games stands at more than 154.7 billion yen.

The Japanese government is aiming to attract 40 million tourists to the country annually.

Last year, the number of overseas tourists to the country reached a record-high 31.88 million, having grown for eight consecutive years. If the Tokyo Olympics are held successfully, the goal of 40 million tourists may not be difficult to achieve. But if the Games are suspended, a large number of international tourists will cancel their plans to visit Japan, leading to a series of losses.

The outbreak has also affected the Japanese tourism industry. On March 2, Luminous Cruising declared bankruptcy, becoming the country's first cruise ship company to go bust due to the virus.

For the IOC, suspending the Games would mean significant losses. It has set up a fund of about $1 billion, which, in addition to hosting the Games, will go to regional, national and international sports governing bodies to fund athletes, according to the committee's website.

But the IOC's financial statements for 2013 to 2016 show that 73 percent of this amount has come from rights to broadcast the Games live, and 18 percent from sponsors, meaning that suspending the Olympics would have an unprecedented economic impact on the committee.

Seiko Hashimoto, Japan's Olympics minister, said this month during a meeting of parliament: "The IOC has the right to cancel the Games only if they are not held during 2020. This can be interpreted to mean the Games can be postponed as long as they are held during the calendar year."

Haruyuki Takahashi, a member of the Tokyo Games organizing committee, told The Wall Street Journal that a delay of one to two years may be the most realistic option.

But according to senior IOC member Dick Pound, with so many stakeholders involved, postponing the Games is not simply a matter of timing. The possibility of postponing or moving them is open to question.

First, if the Games are postponed until the end of this year, low temperatures will have an impact on the outdoor events, particularly athletics. The average temperature in Tokyo in July and August is about 23 C, while in November it drops to 16.7 C, and the minimum temperature falls below 10 C.

Moreover, the number of global sports events scheduled for the next two years will make it difficult for athletes and national teams to coordinate schedules.

In the second half of this year, the professional sporting calendar is tight. Starting in October, National Football League, college football, baseball, basketball and hockey games are due to be staged across North America. In Europe, soccer leagues will either be playing catchup with games postponed from this season, or starting a new list of fixtures.

A delay would also be a test for broadcasters, Pound said. With so many top-level sports events scheduled for the second half of this year, and with the sale of advertising slots during the Games almost guaranteed, broadcasters would be reluctant to accept any rescheduling.

"If the Tokyo Olympics were to be canceled or postponed, it would be difficult for the host country, sponsors and the IOC to bear the losses and difficulties," he added.