Turkish Foreign Minister Hakan Fidan confirmed on Monday the death of US-based cleric Fethullah Gulen, at 83 years old, whom Ankara held responsible for an attempted coup in Turkey in 2016.
"Our nation's determination in the fight against terrorism will continue, and this news of his death will never lead us to complacency," Fidan told a press conference.
Gulen denied involvement in the failed coup, but his movement was designated as a terrorist organization by Turkey.
In April of this year, the Turkish authorities detained 36 people it said were associated with the coup and were part of the Gulen's movement.
Gulen was formerly an ally of Turkey's ruling party but fell out with Turkish President Tayyip Erdogan following disagreements on several subjects.
Gulen has resided in the US since 1999 in self-imposed exile. In 2016, Turkey accused him of leading the failed July coup attempt and asked that the US extradite him.
Erdogan long blamed Gullen and his followers for attempting to create a "parallel state" by penetrating state institutions.
The 2016 coup
Some 300 people were killed, and 1,400 were wounded as a result of the abortive coup.
Following the events, Erdogan announced a state of emergency and arrested thousands of Gulen supporters. An additional tens of thousands were sacked or had their jobs discontinued.
Yonah Jeremy Bob contributed to this report.