Wimbledon has banned Russian and Belarusian players because it is not prepared "to be used to benefit the propaganda machine of the Russian regime", says chairman Ian Hewitt.
The tournament is unlikely to waver on the move, despite criticism from tennis governing bodies and many players.
Wimbledon runs from June 27th to July 10th.
All England Lawn Tennis and Croquet Club in Wimbledon, London. Photo: PHOTOSPORT
"If conditions significantly change, we would happily review. At this point, we're very clear about our intent," chief executive Sally Bolton added.
Russian president Vladimir Putin said the banning of Russian and Belarusian athletes is "discrimination based on nationality".
"We absolutely acknowledge that others will have different views about the decision we have taken," Bolton told BBC Sport.
Wimbledon men's singles champion Novak Djokovic. Photo: Photosport
"But in the context of the government guidance and increasingly serious situation in Ukraine, we really believe it was the only viable option we could take.
"The government did set out clear guidance within which we had to operate, but it is our decision based on the reasons we've set out."
The decision to ban Russian and Belarusian players from this year's tournament was "intensely tough and agonising", Hewitt said.
The All England Club and the Lawn Tennis Association announced the move last week in response to Russia's invasion of Ukraine.
It is the first major tournament to ban tennis players from the two countries. They are also banned from all the UK grass-court tournaments.
Talks are ongoing between Wimbledon and the government over whether Russian and Belarusian coaches and other officials can attend. But Russian journalists will be not be accredited by the All England Club.
"It is an extreme and exceptional situation which takes us far beyond the interest of the tennis world alone," said Hewitt.
"Russia's ongoing invasion has led to catastrophic harm to millions of lives in Ukraine and has been condemned worldwide.
"The UK government has set out directive guidance for sporting bodies and events with the specific aim of limiting Russia's influence. We have taken that guidance into account as we must as a high-profile event and leading British institution.
"Bound to act, we believe we have made the most responsible decision in the circumstances."
What has the reaction to the move been?
The ATP and WTA - the governing bodies of men's and women's professional tennis - said the move was "unfair".
Both organisations are holding meetings in Madrid this week to decide how to react, with one possibility being removing ranking points from the Grand Slam tournament.
Some players including Ukraine's Elina Svitolina welcomed Wimbledon's action, but the former semi-finalist said Russian and Belarusian players who speak out against Russia's invasion should be allowed to compete.
Russian world number eight Andrey Rublev said the Wimbledon ban is "complete discrimination" and "illogical".
Djokovic said he did not support the "crazy" decision, while Martina Navratilova, who won a record nine Wimbledon singles titles, said excluding Russian and Belarusian players was "not the way to go".
Hewitt said Wimbledon had considered "at length" allowing players to compete if they provided specific written declarations.
"Even if we were able to accept players with written declarations we would risk their success or participation at Wimbledon being used to benefit the propaganda machine of the Russian regime - which we could not accept," he added.
"We also have a duty to ensure that no actions we take place the players or families at risk.
"We understand and deeply regret the impact this decision will have on every individual affected and so many people are suffering as a result of this terrible war."
Aryna Sabalenka Photo: PHOTOSPORT
Men's world number two Daniil Medvedev of Russia and women's world number four Aryna Sabalenka of Belarus are the highest-ranked players to be affected.
Russian world number 15 Anastasia Pavlyuchenkova - who called for the war to stop earlier this year - and 17th-ranked Victoria Azarenka of Belarus will also miss out.
What else was announced about this year's Championships?
Wimbledon's annual spring conference is an opportunity for the All England Club to outline and discuss the key issues before the upcoming Championships.
The other headlines announced by Bolton in Tuesday's news conference include:
*Coronavirus: The whole tournament will return to a full capacity for the first time since 2019, after initially having reduced numbers because of Covid-19 measures when it returned in 2021
*That means the showcourts will have 100% seating throughout and up to 42,000 can enter the grounds.
*There is no plan to implement any Covid-19 measures, although vaccination is encouraged.
*Middle Sunday: On the first planned day of play on what used to be a rest day, there will be a half-hour celebration of epic matches and moments, with former champions and special guests attending
*Final-set tie-break: Agreed among the four Grand Slams, final sets that reach 6-6 will be decided by the first-to-10 and by two clear points
*Singles quarter-finals: Matches will be a combination of women's and men's on both Tuesday and Wednesday
*Mixed doubles final: Given a "greater profile" by being moved to the second Thursday and played as the concluding match
-BBC