The Swiss great, a winner of 20 grand slam titles, had hoped to make a farewell Olympic Games appearance last year, only for the pandemic to mean the event was postponed for 12 months.

Both the Japanese government and the International Olympic Committee have not swayed from their stances that the Games will go ahead despite a strong swell of public support for a cancellation.

With Japan struggling to contain the COVID-19 virus, however, and Tokyo still in a state of emergency, there remain major doubts over whether it is realistic for thousands of international visitors to come to the country in July and August.

Federer has heard the confident voices, but he also is aware that many residents of Tokyo are against the Games happening this year.

"Honestly I don't know what to think. I'm a bit between the two," Federer told Swiss television station Leman Bleu.

"I would love to play in the Olympics, win a medal for Switzerland. It would make me especially proud. But if it doesn't happen because of the situation, I would be the first to understand.

"I think what the athletes need is a decision: is it going to happen or is it not going to happen?

"At the moment, we have the impression that it will happen. We know it's a fluid situation. And you can also decide as an athlete if you want to go. If you feel there's a lot of resistance, maybe it's better not to go. I don't know."

Federer, who is returning from a long knee injury lay-off, has played at four previous Olympics, winning doubles gold with Stan Wawrinka at Beijing 2008 and silver in the singles at London 2012, where Andy Murray denied him in the final at Wimbledon.

He is set to play his second comeback tournament next week at the Geneva Open, building up to a French Open appearance, with Wimbledon on the horizon.

He and his wife, Mirka, and their family are likely to be spending several weeks apart as Federer co-operates, where required, with tournament bubbles, limiting the size of player entourages.

"It's going to test a little the situation at home," Federer said. "I've spoken about it a lot with Mirka. Now it's the comeback which is the priority."