The ad in the U.S. was placed by a group called Advocates of Silenced Turkey, which claims to be committed to "give a voice to all people oppressed in Turkey." The group's website is currently banned in Turkey and their ads were seen to be praised by staunch supporters of Gülen.

Turkey, in return, put up billboards across the country, with those in the Kurdish-majority southeastern provinces written in Kurdish.

AKP spokesperson Ömer Çelik said last week that the Gülen movement, which is officially called the Fethullahist Terrorist Organization (FETÖ), is an enemy of Turkey. 

"FETÖ leaders are enemies of humanity and Turkey just like the PKK," Çelik said on March 4, using the abbreviation of Kurdistan Workers' Party, which is designated as a terrorist organization by Ankara, the U.S. and the European Union.

According to Çelik, the Gülenists see Erdoğan as the "biggest obstacle in the face of their plans of treason."