The measure on Thursday is the latest in a series of purges of suspected supporters of a US-based dissident accused of organizing a failed military coup.
Gulen denies any involvement in the coup, in which at least 246 people, excluding the plotters, were killed.
Turkish authorities have dismissed, suspended or placed under investigation tens of thousands of people in state institutions including government ministries, the armed forces and the police over suspected links to Gulen and his movement.
Cavusoglu was speaking to broadcaster NTV, Reuters reported.