PARIS (AP) — Serbian tennis player Novak Djokovic has drawn criticism from Kosovo’s tennis federation as well as the French Sports Minister after offering his thoughts on the clashes in northern Kosovo between ethnic Serbs and police and NATO peacekeepers.

The 36-year-old who has won 22 Grand Slam titles wrote in Serbian on the lens of a courtside TV camera “Kosovo is the heart of Serbia. Stop the violence” after a first-round victory in Paris on Monday.

Speaking to reporters in Serbian, Djokovic said that he thought what he wrote on the TV camera was “the least I could do”.

“I feel responsibility as a public figure… as well as a son of a man who was born in Kosovo,” Djokovic said.

Kosovo’s tennis federation said that Djokovic’s comments were “deplorable” and stoking tensions between Serbia and Kosovo.

French Sports Minister Amélie Oudéa-Castéra said Wednesday that Djokovic’s political message about Kosovo was “not appropriate” and warned the former top-ranked Serb player that he should not do it again.

Speaking on TV station France 2, Oudéa-Castéra said French Open director Amelie Mauresmo spoke with Djokovic and his entourage to insist on the principle of “neutrality” on the field of play.

“When it comes to defending human rights and bringing people together around universal values, a sportsperson is free to do so,” she said, but added that Djokovic’s message was “militant, very political, and must not be repeated”.

French Open organizers indicated in a statement issued Tuesday that no rules had been broken, without mentioning Djokovic by name, saying: “Occasionally, discussions about international news events enter the realm of the tournament, which is understandable.”