The statement follows recent proposals from the International Olympic Committee (IOC) which suggest a pathway is being explored to allow Russian and Belarusian athletes to return to competition, including the 2024 Olympic Games in France, the government added.
The IOC has said a boycott will violate the Olympic Charter and that its inclusion of Russians and Belarusians is based on a UN resolution against discrimination within the Olympic movement.
However, Ukraine and its western allies have pushed for a ban.
"There are serious concerns about how feasible it is for Russian and Belarusian athletes to compete on a neutral basis given they are directly funded and supported by their states," the statement on Monday said.
The British government added that Russia and Belarus can "pave the way for their athletes' full return to the international sports community by ending the war they started."
Earlier this month Ukrainian President Volodymyr Zelenskiy took part in an online meeting attended by 35 ministers and chaired by the UK to discuss the call for the ban.
He pointed out that 228 Ukrainian athletes and coaches died as a result of the Russian aggression.
