Kono, Japan's administrative and regulatory reform minister, spoke at the Reuters Next conference amid concerns that the coronavirus pandemic could prevent the Games from going ahead.
He said the country is still continuing efforts to host the delayed Games, set to open on July 23, but admitted it was far from certain that the event would go ahead.
Earlier this month, a state of emergency was declared in Tokyo in a bid to curb a spike in coronavirus cases in the Japanese capital.
Tokyo today reported a total of 1,502 new cases, with the nationwide figure hitting 6,566.