Olympic chief Thomas Bach said on Wednesday he was "confident" and "optimistic" swimming events in Paris's Seine River will go ahead at the 2024 Games despite recent cancellations due to pollution.
"We still have one year before the Olympic Games, everyone is working on this challenge and I'm very confident that at the time of the Olympic Games, it will be a huge success, which will benefit the entire population," Bach said after inaugurating sports facilities in Vitry-le-Francois in northeastern France.
"We mustn't forget that for a very long time swimming in the Seine was banned," he continued.
"If with these Games, Parisians return to the Seine, also for leisure and for swimming, it's a huge project and I'm optimistic that we're going to achieve a good result."
In recent weeks, test events planned in the Seine could not take place due to excessive E. coli bacteria in the water.
An open water swim race was cancelled, while a triathlon was transformed into a duathlon only involving cycling and running.
A triathlon has never been converted into a duathlon at an Olympics since the sport was added to the programme in 2000.
Asked about such a possibility next year, the IOC president insisted: "During the Games, the Olympic programme is triathlon!."
Paris officials announced at the end of August that a valve malfunction in the city's sanitation network could have caused the pollution.
Paris Mayor Anne Hidalgo has promised that Parisians should be able to return to swimming on three sites in the Seine in 2025, just over 100 years after it was banned.