In his remarks on the group which orchestrated last year's July 15 coup attempt in Turkey, Erdogan referred to the thousands of suspected FETO members who have been arrested since the defeated coup, which led to 250 people being martyred.
"That one in Pennsylvania cannot leave there,” Erdogan said, referring to FETO leader Fetullah Gulen, who has lived in the U.S. for 18 years.
"Where did he seek refuge? He sought refuge in America. He is living on 400 acres of land reserved for him since 1999, with [people] as good as his slaves…
"Those who have been party to this cruelty with you [Gulen] will give account for that."
Ankara has been seeking the extradition of Fetullah Gulen from the U.S. since last year’s attempted coup.
Gulen has been indicted in several cases relating to the defeated coup bid in Turkey.
Erdogan said they knew of some people who called each other on the night of the coup and "screamed out of joy".
He added that they were not sharing this with the media "for now".
"However, we do share them privately with some people at international meetings. Nobody should deceive anyone. We know very well who is who," Erdogan said. "Therefore, from now on, we will not let some individuals from certain countries run wild here [in Turkey]."
Erdogan also commented on the presence of the PKK in Europe, saying PKK terrorists could not take shelter in Turkey anymore.
"Now they are roaming the streets of Berlin. They roam in Paris and Austria," he said.
Erdogan said this was happening although PKK was supposedly not welcome in the EU, which considers it a terrorist organization.
"Then how come they can walk around under police supervision? How come they can put up the posters of the PKK head on public buildings?" Erdogan asked, saying this was an "act of collusion".
The PKK, listed as a terrorist organization by Turkey, the EU, and US, resumed its decades-long armed campaign in July 2015. Since then, it has been responsible for the deaths of more than 1,200 Turkish security personnel and civilians, including a number of women and children.