International Olympic Committee President Thomas Bach said Wednesday he accepts that the coronavirus-hit Tokyo Games will have to be cancelled if they cannot be held in 2021.
"You cannot forever employ 3,000 or 5,000 people in an organizing committee," Bach said in an interview with BBC Sport.
"You cannot every year change the entire sports schedule worldwide of all the major federations. You cannot have the athletes being in uncertainty," he said.
Bach said Japanese Prime Minister Shinzo Abe had made it clear to him there is no Plan B if the games are delayed beyond next summer.
On March 24, Abe announced the decision to delay the start of the Tokyo Olympic and Paralympic Games, originally set to begin this summer, until 2021.
Under the new timetable, the Olympics will start on July 23, 2021 and run until Aug. 8. The Paralympics will run from Aug. 24 until Sept. 5, 2021.
The Olympics were last canceled in 1944 because of World War II, but they have never before been moved or delayed in their 124-year modern history.
Speaking in the Japanese parliament last month, Abe said the games cannot be held in a "complete form" if the pandemic is not contained. He stressed the importance of developing vaccines and drugs to combat the coronavirus before the games begin next year.
The 2022 Beijing Winter Olympics are due to take place in China just six months after the Tokyo Games.
Asked whether the Olympics could be staged behind closed doors, Bach told BBC, "This is not what we want."
"Because the Olympic spirit is about also uniting the fans and this is what makes the games so unique that they're in an Olympic stadium, all the fans from all over the world are together," he said.
"But when it then would come to the decision...I would ask you to give me some more time for consultation with the athletes, with the World Health Organization, with the Japanese partners."