Ukraine could boycott the 2024 Paris Olympics if Russian and Belarusian athletes are allowed to compete, says the country's sports minister.
The International Olympic Committee said on Wednesday it would "explore a pathway" for athletes from the two countries to take part as neutrals.
The UK Government has condemned the plan as a "world away from the reality of war".
"Our position is unchanged," said Ukraine sports minister Vadym Guttsait.
"As long as there is a war in Ukraine, Russian and Belarusian athletes should not be in international competitions."
Writing on his official Facebook page, Guttsait said that Ukraine's sporting bodies need to "strengthen communication" with international federations to keep the ban in place and are working on "further possible steps" to continue sanctions.
He added: "If we are not heard, I do not rule out the possibility that we will boycott and refuse participation in the Olympics."
Guttsait, who is also president of Ukraine's National Olympic Committee, said their executive committee has started consulting national sports federations over a possible boycott.
"I hope all the federations, athletes and the entire civilized world pay attention now and we won't have to resort to extremes," he added.
Ukraine's president Volodymyr Zelensky has said Russian athletes should have "no place" at the Paris Games.
Culture Secretary Michelle Donelan said the UK Government "condemns any action that allows President Putin to legitimise his illegal war in Ukraine".
"This position from the IOC is a world away from the reality of war being felt by the Ukrainian people - and IOC president [Thomas] Bach's own words less than a year ago where he strongly condemned Russia for breaking the Olympic Truce and urged it to 'give peace a chance'," she added.
"We, and many other countries, have been unequivocal on this throughout, and we will now work urgently across like-minded countries to ensure that solidarity continues on this issue."
The IOC previously asked sporting federations to exclude athletes from the countries following Russia's invasion of Ukraine last year. However, Wednesday's statement said "no athlete should be prevented from competing just because of their passport".
Last month, Bach spoke of not wishing to punish individual athletes for the actions of their governments.
However, in response to the IOC statement, World Athletics stressed that athletes from those countries remained excluded from its events.
The athletics governing body outlined that Russian athletes were suspended over the country's doping scandal and also - alongside Belarusian athletes - for the invasion of Ukraine.
It added that a taskforce will report in March on whether "the intensive work we have conducted in cleaning up athletics in Russia has now been sufficiently embraced for the doping-related suspension to be lifted".
If that suspension is lifted, World Athletics said its council meeting would then consider the ongoing suspension of Russian and Belarusian athletes and officials in relation to the invasion of Ukraine.
Russian and Belarusian athletes will, though, be able to take part in this year's Asian Games, the Olympic Council of Asia (OCA) has said.
It said: "All athletes, regardless of their nationality or the passport they hold, should be able to compete in sports competitions."
Meanwhile, the International Paralympic Committee said it would "follow with interest" the IOC's decision.
"We wish to reiterate that we hope and pray that the conflict comes to an end, that no more lives are taken, and that we can run sports and politics separately," IPC president Andrew Parsons added.
Russia and Belarus were suspended by the IPC with immediate effect last year for their "inability to comply with membership obligations".
BBC