John Bass posted a picture on his Instagram account with his normally dark hair digitally altered to a reddish blond. The caption said: "American Diplomats: We Are All Blonde."
Ankara Mayor Melih Gokcek had taken to social media to go after State Department spokeswoman Marie Harf for criticizing Turkish police tactics during demonstrations.
Earlier this week, Gokcek posted a tweet with an image of police in Baltimore forcibly subduing someone during the recent unrest with a caption that said: "Where are you stupid blonde, who accused Turkish police of using disproportionate force?"
When asked about the Tweet, Harf has said that she did not want to dignify it with a response.
Gokcek, a longtime mayor of Ankara, is a close ally of Turkish President Recep Tayyip Erdogan. Gokcek is a cantankerous presence on social media, which he often uses to go after foes of his party. He was also outspoken during the large anti-government protests in 2013, attacking protesters and journalists.