A Trump post showed the country, along with Canada, Cuba, Mexico and Greenland, covered in red, white and blue, and labeled "United States of America."
The mayor of Cagnes-sur-Mer, on the French Riviera, said that two of the four works had been recovered but that the two perpetrators are still being sought.
Canadian countertariffs on $20 billion worth of U.S. imports came into effect Tuesday, as Bombardier said it valued its partnership with American companies.
Remarks by at a regional conference underscored the challenge Washington faces in trying to impose economic pain on Iran while not harming its closest neighbors.
Secretary of State Marco Rubio will visit friendly governments in Colombia, Ecuador and Peru. But his support for the Venezuela oil deal is rankling some in the region.