ANKARA, Sept. 13 (Xinhua) — Turkish Justice Ministry officially asked the U.S. to arrest cleric Fethullah Gulen for ordering coup attempt on July 15, Hurriyet News reported Tuesday.

Ankara accuses Gulen of giving the order for the failed coup attempt and commanding it, a charge he denies.

Turkish President Recep Erdogan told media that Turkey is disappointed that Gulen is still at large in the U.S., who should be detained according to extradition treaty.

"According to the 1981 extradition treaty with U.S., we expect Gulen to be detained, however he still roams freely," Erdogan said during a joint press conference with visiting U.S. Vice President Joe Biden on Aug. 24 in Ankara.

Turkey has repeatedly demanded Gulen's extradition following the attempted coup, with U.S. officials insisting that they can only extradite him if Turkey presents proof regarding his direct involvement in the coup

Early in September, a delegation from the ruling Justice and Development Party (AKP) went to Washington to discuss the extradition.

Turkish Justice Ministry had already sent dossiers to the U.S. Justice Department which it said contained evidence of Gulen's involvement in the coup attempt.