NEW YORK — Munich Mayor Dieter Reiter has threatened to remove Valery Gergiev as chief conductor of the Munich Philharmonic unless Gergiev publicly says by Monday that he does not support Russia’s invasion of Ukraine.

The Rotterdam Philharmonic Orchestra also said it would drop the 68-year-old Russian’s planned festival there this September if he does not stop supporting Russia President Vladimir Putin.

Carnegie Hall said Friday it was canceling two performances in May of the Mariinsky Orchestra that were to be led by Gergiev. The institution cited “recent world events” and the pandemic, adding they would not reschedule the shows. The move comes a day after the Vienna Philharmonic dropped Gergiev as conductor in a five-concert U.S. tour that starts at Carnegie Hall on Friday.

Gergiev is close to Putin and supported Russia’s annexation of Crimea in 2014.

“I have made my position clear to Valery Gergiev and have asked him to clearly and unequivocally distance himself from the brutal invasion that Putin is waging against Ukraine and now in particular against our twin city, Kyiv,” Reiter said in a statement Thursday. “If Valery Gergiev does not take a clear stance by Monday, he can no longer remain chief conductor of our philharmonic.”

Gergiev has been Munich’s chief conductor since the 2015-16 season. He was principal guest conductor in Rotterdam from 1995 to 2008, and the orchestra began an annual Gergiev Festival in 1996.

“In the event that Valéry Gergiev does not openly distance himself from President Putin’s actions in Ukraine, we will be forced to cancel all concerts conducted by Valéry Gergiev including the Gergiev Festival that would take place in September,” the Rotterdam Philharmonic said in a statement.

He also is music director of the Mariinsky Theatre in St. Petersburg, Russia, and the White Nights Festival there.

In addition, the Royal Opera House on Friday canceled a planned tour to London by Moscow’s Bolshoi Ballet.

The Mariinsky and Bolshoi are among Russia’s most renowned arts institutions.

“A summer season of the Bolshoi Ballet at the Royal Opera House had been in the final stages of planning,” The Royal Opera said in a statement. “Unfortunately, under the current circumstances, the season cannot now go ahead.”

Milan’s Teatro alla Scala also sent a letter to Gergiev on Thursday asking him to make a clear statement in favor of a peaceful resolution in the Ukraine, or he would not be permitted to return to complete his engagement conducting Tchaikovsky’s “The Queen of Spades.”

Milan Mayor Giuseppe Sala, who is La Scala’s president, said the request was made because Gergiev had declared his closeness to Russian President Vladimir Putin on multiple occasions.

La Scala said Friday it had not yet received a response.

Online posts in recent days had promised protests at Carnegie Hall, where Gergiev was to lead the Vienna Philharmonic on Friday and Saturday nights, and Sunday afternoon. The orchestra then travels to Hayes Hall in Naples, Florida, for performances on Tuesday and Wednesday.

Metropolitan Opera music director Yannick Nézet-Séguin will replace Gergiev for the Carnegie concerts.

Semyon Bychkov, another top-level Russian conductor, issued a statement critical of the Russian government, The 69-year-old is music director of the Czech Philharmonic and was music director of the Orchestre de Paris from 1989-98. He emigrated to the U.S. in 1975 and has lived in Europe since the 1980s.

“Silence in the face of evil becomes its accomplice and ends up becoming its equal. Russian aggression in Ukraine brings us to what my generation hoped would never happen again: War,” Bychkov said. “One has to be demented to refer to the collapse of the Soviet Union as the greatest tragedy of the 20th century, which is how Putin defined it, rather than rejoice at the fact that it happened without bloodshed and brought an end to the kidnapping of many nations in addition to Russia itself.”

Chicago Symphony Orchestra music director Riccardo Muti took the rare step to address the audience before a performance of Beethoven’s Ninth Symphony at Orchestra Hall on Thursday night.

“What I, we are seeing on television is horrible,” Muti said. “And, tonight in the final movement of the symphony, Beethoven taking the text from Schiller, he speaks about joy, joy, joy. But we will think in that moment that joy without peace cannot exist. And so I hope that from this wonderful hall — from the orchestra, from the chorus, from you — a message should arrive to all the people that not only in Ukraine but in world (who) are creating violence, hate, and a strange need for war: we are against all that.”

The Berlin Philharmonic dedicated this weekend’s performances of Mahler’s Second Symphony to those affected by the invasion.

“Putin’s insidious attack on Ukraine, which violates international law, is a knife in the back of the entire peaceful world,” chief conductor Kirill Petrenko said. “It is also an attack on the arts, which, as we know, unite across all borders. I am in complete solidarity with all my Ukrainian colleagues and can only hope that all artists will stand together for freedom, sovereignty and against aggression.”