Ukrainian President Volodymyr Zelensky says that allowing Russia to compete at the 2024 Olympics in Paris would amount to showing that “terror is somehow acceptable”.
He said he had raised the issue with French President Emmanuel Macron.
Moscow must not be allowed to use the Olympics for propaganda, he added.
The International Olympic Committee (IOC) has said Russian and Belarusian athletes could compete as neutrals at the Olympics.
But Ukraine has threatened to boycott Paris 2024 if Russian and Belarusian athletes are allowed to compete.
Attempts by the IOC “to bring Russian athletes back into the Olympic Games are attempts to tell the whole world that terror is somehow acceptable”, Mr Zelensky said in his nightly video address.
Russia must not be allowed to use the Games “or any other sport event as propaganda for its aggression or its state chauvinism”, he added.
The IOC said this week that Russian and Belarusian athletes could compete as “neutral athletes”, stating that “no athlete should be prevented from competing just because of their passport”.
But Mr Zelensky says there can be no neutrality in sport while his country’s athletes are dying on the battlefield.
He also drew comparison with the 1936 Olympic Games in Berlin when the Nazis were in power.
“There was a major Olympic mistake,” he said. “The Olympic movement and terrorist states definitely should not cross paths.”
The UK government has also condemned the plan to allow athletes to compete neutrally as a “world away from the reality of war”.