US-based preacher Fethullah Gulen has condemned Turkey's judicial system after a court issued an arrest warrant which accuses him of ordering last month's bid to topple President Recep Tayyip Erdogan.

"It is well-documented that the Turkish court system is without judicial independence, so this warrant is yet another example of President Erdogan's drive for authoritarianism and away from democracy," he said in a statement late on Thursday.