Bill Gates says Tokyo Olympics' fate depends on vaccine roll-out: Kyodo
"But you know, I think it's still possible if things go well."
He added: "If things don't go well, that would be unfortunate, but you know, we're doing our best to help those vaccines get approved and get going for the entire world."
With Covid-19 still a major problem across the globe, doubts have been growing over the feasibility of holding the Olympics this year, although organisers insist the delayed event will go ahead.
The International Olympic Committee said this week it was determined to hold a "safe and secure" Tokyo Games, and urged participants to be vaccinated.
The IOC is due to hold an executive board meeting on Wednesday, with Tokyo 2020 on the agenda.