Governments of more than 30 countries have asked the IOC for "clarification" on Monday over how Russian and Belarusian athletes would be able to compete as neutral athletes in the Paris 2024 Olympics.
Russia and its ally Belarus, which allowed its territory to be used as a launching pad when Moscow began its invasion of Ukraine last February, have been sidelined from most Olympic sports since the war began.
The International Olympic Committee has said it is exploring a "pathway" to allow Russian and Belarusian competitors to take part in the Paris Games under a neutral flag, sparking fury from Ukraine.
But in a joint letter the countries, including the US, France, Britain and Canada, expressed concern particularly given the "strong links and affiliations between Russian athletes and the Russian military".
"We have strong concerns on how feasible it is for Russian and Belarusian Olympic athletes to compete as 'neutrals' … when they are directly funded and supported by their states," the letter said.
It said that "these strong concerns need to be dealt with by the IOC".
The joint letter to the IOC follows a summit this month in London attended by France, Britain, the US and Canada, among others.
Ukrainian President Volodymyr Zelenskyy also spoke at the conference.
"We firmly believe that, given there has been no change in the situation regarding the Russian aggression in Ukraine … there is no practical reason to move away from the exclusion regime for Russian and Belarusian athletes set by the IOC," the letter read.
"As long as these fundamental issues and the substantial lack of clarity and concrete detail on a workable 'neutrality' model are not addressed, we do not agree that Russian and Belarusian athletes should be allowed back into competition."
