Speaking to the UN General Assembly, Mr Erdogan declared "necessary measures" need to be taken against US-based Mr Gulen who he holds accountable for the aborted coup d'etat against him in July.
Mr Gulen, who fled Turkey for Pennsylvania, has strongly denied the charges he orchestrated or was even involved in the recent military coup.
Mr Erdogan said: "I would like to call on all our friends to take the necessary measures against the Fethullah Terrorist Organisation [FETO] in their own countries for the future of their own people and their well-being."
"This terrorist organisation is in a deep mental heresy of subduing the whole world, far beyond Turkey.
"It is evident from our experience that if you do not fight against FETO now, tomorrow may be too late."
Mr Erdogan's government has suspended thousands of teachers and military personnel in an attempt to purge them of Gulen supporters.
He told the UN Mr Gulen's movement is active in 170 countries posing a "national security threat" to them all, AFP reports.
The Turkish President has also repeatedly called on the United States to extradite Mr Gulen
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