Thomas Bach has rejected claims the IOC was too slow in postponing the Tokyo Olympics and hit out at "conspiracy theories" regarding the decision.
It was confirmed last month the 2020 Games, originally scheduled to begin on July 24, would be put back by a year due to ongoing concerns over athletes' health and ability to train amid the coronavirus pandemic.
The IOC came in for criticism for having originally insisted the Games would go ahead as planned before pressure arrived from several federations, with Canada and Australia among the nations to say they would not have sent athletes if the Olympics went ahead on the planned dates this year.
IOC president Bach said the decision to postpone required unilateral support, while insisting the intention was never to cancel the Games completely.
Speaking to Welt Am Sonntag, Bach said: "In such emotional situations, as a responsible person, you cannot make decisions based on gut instinct.
"We really cannot be accused of hesitation or lack of advice and transparency.
"In order to counter conspiracy theories, it must be said clearly that the IOC was insured against a cancellation, but not insured in the case of a postponement.
"For a postponement, however, the approval of the organising committee, which must be willing to work a year longer, is required, and the Japanese government must be willing to continue to support the preparations.
"We weren't dealing with the postponement of a football match or city marathon here. We were dealing with 11,000 athletes from all over the world; 50 world championships in 33 different sports, all in the same place and within the space of 16 days as well as partners in the worlds of sport, business and politics, all of whom had to be brought on board.
"Two days later, I reached agreement with the prime minister of Japan, Shinzo Abe, that the Games should be rescheduled.
"I would ask people to remember that, at that point, there were still discussions going on about an April date for the Bundesliga and Champions League to start up again. Wimbledon was still in the calendar. Even now, the Tour de France has still not been cancelled."
Bach added he did not know what the cost of postponing the Games would be but acknowledged it would run into "several hundred million dollars".
"That is impossible to say for now. We agreed with the prime minister that Japan will continue to cover the costs it would have done under the terms of the existing agreement for 2020, and the IOC will continue to be responsible for its share of the costs," he said.
"For us, the IOC, it is already clear that we shall be faced with several hundred million dollars of additional costs."
There have been suggestions that uncertainty over the COVID-19 crisis could lead to another postponement, a scenario Bach would not be drawn on.
"The top priority, of course, remains the health of the athletes and everyone involved in the Games and the containment of the virus," Bach said.
"We will use this as a basis for all future decisions."