Aviation communication world wide by international convention is conducted in English, at least at the level of commercial and civil air, and I’d expect it’s the lingua franca for warning off “errant” military aircraft as well. The French are probably still offended by this, but they do have “Mayday” (m’aidez = “Help Me”) as the ultimate emergency message.
“pan-pan” is also a distress communication. May-Day used more for life threatening situations and pan-pan used more for serious aircraft failure, becoming lost or any other situation that requires communication and assistance from the ground.