Male players will not receive ranking points at Wimbledon following the decision to ban Russian and Belarusian stars from the tournament.
Players from the countries have been banned by the All England Lawn Tennis Club from all UK grass-court events after the Russian invasion of Ukraine.
However, ATP events outside Wimbledon, such as Queen’s, will retain their ranking points.
“It is with great regret and reluctance that we see no option,” said the ATP.
The decision means Serbia’s Novak Djokovic – the defending men’s champion – will lose his status as the world number one.
Djokovic, a six-time champion at the All England Club, will be unable to retain the 2,000 ranking points he earned by winning the title last year and is only 680 ahead of nearest rival Daniil Medvedev.
The Women’s Tennis Association (WTA) has not announced whether it will follow the decision taken by the men’s governing body.
Announcing the move, the ATP said: “Unilateral decisions of this nature [by Wimbledon], if unaddressed, set a damaging precedent for the rest of the tour.
“Discrimination by individual tournaments is simply not viable on a tour that operates in more than 30 countries.”
It added: “We remain hopeful of further discussions with Wimbledon leading to an acceptable outcome for all concerned.”
UK Culture Secretary Nadine Dorries wrote to ATP and WTA bosses earlier this week urging them not to “penalise the AELTC” and said it would send a “completely wrong message to both Putin and the people of Ukraine”.
Shortly before the decision was announced on Friday, British men’s number two Dan Evans told the BBC he did not agree with ranking points being stripped.
“If we’re sticking it solely on tennis and not politics there should be points for Wimbledon,” he said in a pre-tournament interview at the French Open.
The men’s ATP events include Queen’s and Eastbourne in the build-up to Wimbledon, and there are three WTA tournaments in Nottingham, Birmingham and Eastbourne.
Ranking points are used to decide where a player is seeded and whether or not they can gain direct entry into a tournament.
Wimbledon bosses consulted with the UK government before announcing the decision to ban players, stating it would be “unacceptable for the Russian regime to derive any benefits from the involvement of Russian or Belarusian players” at this summer’s Grand Slam.
The Lawn Tennis Association then joined Wimbledon in barring players from domestic tournaments – but the stance has been criticised by a number of players.
Russian world number two Medvedev, also speaking at Roland Garros, said there were “a lot of mistakes” behind the decision.
The US Open champion added he would accept the decision and had not considered taking legal action to reverse it.
Players from both countries have been allowed to compete on the tennis tour, including at this month’s French Open, but not under their national flags.
“We should be playing for ranking points at Wimbledon and it will be disappointing for me as a Brit if we’re not,” said Evans.
“I think the majority of the players think it is not ideal the other players can’t play but there should still be points at Wimbledon. In my opinion they are only trying to protect the Russian players by letting them play.
“There are a lot of other people losing out because of a very small minority of players who are missing the tournament.”
Russia was previously banned from defending its Davis Cup and Billie Jean King Cup team titles after the country’s invasion of Ukraine – a war supported by Belarus.
The ATP and the WTA have suspended their combined event scheduled to take place in Moscow in October.
The International Tennis Federation (ITF) has also cancelled its events in the country.
