Turkish President Recep Erdogan (R) and visiting U.S. Vice President Joe Biden attend a joint press conference in Ankara, Turkey, Aug. 24, 2016. (Xinhua/Mustafa Kaya)

ANKARA, Aug. 24 (Xinhua) -- Turkey is disappointed that cleric Fetullah Gulen, who should be detained according to extradition treaty, still roams freely, Turkish President Recep Erdogan told media on Wednesday in Ankara.

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

However, Biden said only the U.S. federal courts have the power to extradite Gulen to Turkey, "God Willing there will be enough evidence to meet criteria which Turkey seeks on Gulen," Biden said.

At the press conference, Erdogan also confirmed the Free Syrian Army (FSA), Syria's opposition forces, has forced the militants in Jarablus of northern Syria out with the help of Turkish forces and the U.S.-led coalition forces.

"The FSA and Jarablus forces have retaken the town and the IS has left," he said, adding that the aim of Turkish forces enter Syria is to fight terrorist groups and protect the border of Turkey.

"We believe the Turkish border must be controlled by Turkey only, there should be no occupation by other group," Biden said.