Ukraine's Volodymyr Zelensky is expected to urge world leaders to oppose the prospect of Russian and Belarusian athletes at the upcoming Olympics.
The International Olympic Committee (IOC) has come under fire after it moved to water down the outright ban on delegates from both countries at the 2024 Games.
It is considering whether Russians and Belarusians could be able to compete as neutrals during the contest in Paris next year.