Let's hope Donald Trump wasn't planning on taking his private jet to Europe anytime soon: The number of cities that would welcome him is shrinking by the day.

Paris Mayor Anne Hidalgo became the latest head of a European capital to speak out against the presumptive U.S. Republican presidential nominee.

“Mr. Trump is stupid,” Hidalgo said this week while meeting with new London Mayor Sadiq Khan -- also not a Trump fan. "He’s very stupid. My God."