Japan's prime minister has assured the IOC that the leak of radioactive water from the Fukushima nuclear plant is "under control" and will never affect Tokyo.
Tokyo is competing against Madrid and Istanbul, with all three cities making their final presentations ahead of a vote later Saturday by the International Olympic Committee.
Tokyo has been considered a slight favorite but has been on the defensive in the final days of the campaign amid mounting concerns about the Fukushima leak.
Prime Minister Shinzo Abe spoke forcefully about the Fukushima situation, saying in English: "Let me assure you the situation is under control. It has never done and will never do any damage to Tokyo."
Based on reporting by The Associated Press.