The Olympic marathon and race-walking events during Tokyo 2020 will be moved from the capital to Japan's northernmost island of Hokkaido due to worries about heat.
The IOC's statement said it was planning to move the events to Sapporo, which would mean "significantly lower temperatures for the athletes during the Olympic Games".
"Athletes' health and well-being are always at the heart of our concerns," IOC president Thomas Bach said in a statement.
"The Olympic Games are the platform where athletes can give 'once-in-a-lifetime' performances and these measures ensure they have the conditions to give their best."
But Tokyo 2020 organisers appeared to think the move was just a proposal and that further discussions would take place at their coordination commission meeting planned for the end of this month.
"Working closely with the Tokyo Metropolitan Government, the Tokyo 2020 organising committee will discuss this matter with the concerned parties at the upcoming IOC Coordination Commission meetings," a Tokyo 2020 statement said.
International Association of Athletics Federations head Sebastian Coe said his organisation would work with the IOC and Tokyo 2020 on any new plan.
"[We] will continue to work with the IOC and Tokyo 2020 on the proposal to move the road events to Sapporo," Coe said.
"Giving athletes the best platform for their performances within the environment they are in is central to all major events."
Organisers had been looking for ways to protect athletes and spectators from Tokyo's sweltering temperatures expected during next year's Summer Olympics and Paralympic Games.
Tokyo held a test marathon in September, featuring tents equipped with mist machines for spectators. Officials had also planned to hold longer-distance races during cooler hours, but questions had persisted over whether such steps were enough.
Suffocating humidity and high temperatures at the recent world championship marathons in Doha proved gruelling, despite a midnight start.
Temeperatures were still 29.09C with 48.6 percent humidity at the start of the marathons and nearly a third of the 70 starters failed to reach the finish-line, fuelling debate over athletes' welfare.
Temperatures in Tokyo during July and August, when the city hosts the Olympic and Paralympic Games, commonly exceed 30C, with high humidity adding to the discomfort.
Sapporo's temperatures during the period are as much as 5-6 degrees centigrade cooler during the day than in Tokyo, the IOC said.