Cancelling the 2020 Olympics is "unthinkable" although the classification of the coronavirus as a pandemic will likely have some impact on the Games, the Tokyo city governor said on Thursday.
"It can't be said that the announcement of a pandemic would have no impact... But I think cancellation is unthinkable," Yuriko Koike told reporters.
Doubts are increasingly being raised over whether the Olympics can be held as scheduled from July 24 to August 9.
Organisers have insisted the Games will go ahead as planned and the International Olympic Committee (IOC), with whom the final decision rests, has said there has not yet been any talk of cancellation or postponement.
The IOC has said it will coordinate closely with the World Health Organisation, which has now officially classified the outbreak as a pandemic.
But coronavirus has already taken a huge toll on sport across the globe.
US basketball was the latest sport to be hit, as the NBA said it would suspend play starting on Thursday after a Utah Jazz player preliminarily tested positive for COVID-19.
In Italy, the hardest-hit European country, all sporting events including Serie A have been suspended until April 3.
Arsenal's game at Manchester City on Wednesday became the first Premier League fixture to be called off due to the outbreak, with the Gunners' players put in quarantine after coming into contact with the owner of Greek club Olympiakos.
The virus has also hit the UEFA Champions League, with Italian side Atalanta qualifying for the quarter-finals at Valencia on Tuesday in an empty stadium, while Paris Saint-Germain's win over Borussia Dortmund was also played without spectators.
In tennis, the prestigious ATP and WTA Indian Wells tournament was cancelled as California health officials declared a public health emergency in the area after a confirmed case of the coronavirus.