Wimbledon has banned Russian and Belarusian players from the 2022 tournament in response to the invasion of Ukraine, but men's tour organizers the ATP branded the move "unfair" on Wednesday.
The All England Lawn Tennis Club, which runs Wimbledon, said it was acting to "limit Russia's global influence through the strongest means possible."
Russian men's world No. 2 Daniil Medvedev and Belarusian female world No. 4 Aryna Sabalenka — a Wimbledon semi-finalist last year — are the leading players affected by the ban.
"In the circumstances of such unjustified and unprecedented military aggression, it would be unacceptable for the Russian regime to derive any benefits from the involvement of Russian or Belarusian players," an AELTC statement said.
"It is therefore our intention, with deep regret, to decline entries from Russian and Belarusian players to Wimbledon."
The Lawn Tennis Association has also banned Russian or Belarusian players from competing in British grass-court tournaments, including Wimbledon warm-up events at Queen's Club and Eastbourne.
Players from Russia and Belarus have been able to compete on the ATP and WTA tours since the war in Ukraine started, but they were not allowed to use their national flags.
The ITF had already banned both countries' teams from the Davis Cup and the Billie Jean King Cup.
ATP bosses claim the Wimbledon ban is discriminatory and sets a damaging precedent.
"We believe that today's unilateral decision by Wimbledon and the LTA to exclude players from Russia and Belarus from this year's British grass-court swing is unfair and has the potential to set a damaging precedent for the game," an ATP statement said.
"Discrimination based on nationality also constitutes a violation of our agreement with Wimbledon that states that player entry is based solely on ATP Rankings.
"Our sport is proud to operate on the fundamental principles of merit and fairness, where players compete as individuals to earn their place in tournaments based on the ATP Rankings."
Players still set for Roland Garros
Others hit by the ban are Russia's Andrey Rublev, who is currently eighth in the ATP rankings, while his compatriot Karen Khachanov is in 26th place.
Russian world No. 15 Anastasia Pavlyuchenkova and Victoria Azarenka of Belarus are two of the other top female players who will miss the grass-court Grand Slam.
Wimbledon, the most high-profile of tennis's four Grand Slam events, runs from June 27 to July 10 this year.
At present, Russian and Belarusian players are still able to compete at the French Open, which starts in May.
"On behalf of the All England Club and the Committee of Management of The Championships, we wish to express our ongoing support for all those impacted by the conflict in Ukraine during these shocking and distressing times," the AELTC statement said.
"We share in the universal condemnation of Russia's illegal actions and have carefully considered the situation in the context of our duties to the players, to our community and to the broader U.K. public as a British sporting institution.
"Given the profile of The Championships in the United Kingdom and around the world, it is our responsibility to play our part in the widespread efforts of Government, industry, sporting and creative institutions to limit Russia's global influence through the strongest means possible."
Wimbledon chiefs spoke to the British government earlier in April to discuss whether they should follow a similar policy to the men's and women's circuits.
"We recognize that this is hard on the individuals affected, and it is with sadness that they will suffer for the actions of the leaders of the Russian regime," AELTC chairman Ian Hewitt said.
The AELTC statement added that the ban would be reconsidered if circumstances "change materially" between now and June.
Russia reacted angrily to the reports, deeming it "unacceptable."
"Once again they simply turn athletes into hostages to political prejudice, political intrigues," Kremlin spokesman Dmitry Peskov told reporters.
"This is unacceptable. Taking into account that Russia is a very strong tennis country, our athletes are at the top of world rankings, the competition itself will suffer from their removal."