BUCHAREST, Romania — The U.S. ambassador to Romania has caused a stir in the eastern European country by posing for a photo holding a flag of an ethnic Hungarian minority group.

The picture of Ambassador Hans G. Klemm holding the Szekler flag was posted on Facebook Tuesday by Antal Arpad, the mayor of the town of Sfantu Gheorghe, which Klemm visited. Arpad and two other men were also holding the flag in the undated photo.

The Szekler group is a vocal minority living in Transylvania, which was part of the Austro-Hungarian Empire until 1918. Some Hungarians want it to be part of Hungary again and the Szeklers have been seeking more autonomy. There are about 1.2 million ethnic Hungarians living in Romania, most in Transylvania.

A comment next to the photo in Romanian and Hungarian said Szeklers are a suppressed minority because it is illegal to fly their flag on public buildings.

Romanian law allows public buildings to fly only the Romanian flag, the European Union flag or a flag representing the public institute where it is displayed.

The Romanian foreign ministry said Wednesday it had talked to U.S. diplomats about “the necessity to understand and take into consideration … certain sensibilities.”

The U.S. embassy said Klemm “regularly travels throughout the country, meeting with diverse groups from all parts of Romanian society,” and praised Romania’s commitment to democracy.