Novak Djokovic's political message about Kosovo at the French Open was "not appropriate" and "shouldn't happen again", says France's sports minister.
Amelie Oudea-Castera said there needs to be a "principle of neutrality for the field of play".
Serb Djokovic wrote "Kosovo is the heart of Serbia. Stop the violence" on a camera lens.
It is in reference to recent tension in Kosovo, which declared independence from Serbia in 2008.
Serbia has never recognised Kosovo's independence and there has been violence in the past days following the installation of ethnic Albanian mayors in the north of the country, with police and Nato troops clashing with Serb protesters.