FACTBOX - Tokyo Olympics in the shadow of coronavirus

Although the global situation has improved from a year ago, when the Games were postponed for the first time except for war, flare-ups of the disease worldwide mean organisers must hold the sporting extravaganza under strict rules to limit its spread.

Here is a look at the circumstances of these unprecedented Olympics, the second time Tokyo has hosted them since 1964.

Foreign spectators have been banned, and organisers are expected to make a decision late this month on domestic spectators.

Toshiaki Endo, vice president of the Tokyo organising committee, told Reuters some spectators could be allowed into venues, although he personally preferred a total ban to calm persistent public opposition to the Games.

The government is considering requiring those who attend to show either negative COVID-19 test results or vaccination records, media said. Bans on loud cheering or high-fives are among other possible steps.

While recent opinion polls show some shift towards approval for the Games, earlier surveys revealed that 60% to 80% of respondents would have liked them either cancelled or postponed again. However, the International Olympic Committee (IOC) has said the findings will not affect plans to hold the Games.

The Games have already lost meaning and Japan has been "cornered" into pressing ahead, Kaori Yamaguchi, a member of the country's Olympic panel and a judo medallist, wrote in an opinion piece this month.

By the end of May, a growing number of investors in Japanese stocks believed that cancelling the Games would be better for the market. At the same time, a Reuters survey found that nearly 70 percent of businesses also wanted either another postponement or cancellation.

Many sponsors are uncertain how to proceed with advertising campaigns or marketing events because they do not know if domestic spectators will be allowed into the venues, sources at companies directly involved in sponsorship told Reuters.

Some business leaders have been even more outspoken. In May, Hiroshi Mikitani, who heads e-commerce giant Rakuten Group Inc , said Japan's low vaccination rate made it a "suicide mission" to host the Games.

Doctors have warned that the Games' need for medical staff could pressure a healthcare system already stressed by caring for virus patients, and officials in some areas have said they would not prioritise Olympics-related patients.

Organisers, though, said in late May they had lined up about 80% of the staff needed, with target numbers cut about a third from 10,000 originally.