Turkey's prime minister said Saturday he wants the United States to place Islamic preacher Fethullah Gulen, blamed for plotting a coup, under "temporary arrest," ahead of a visit by Vice President Joe Biden next week.
Gulen, a one-time ally turned rival of Turkish President Recep Tayyip Erdogan, denies the charges that he plotted the failed coup on July 15. The cleric lives in Pennsylvania.
A senior US official told reporters in Washington on Friday that Turkey so far only has requested Gulen's return on criminal charges not related to the coup.
The official, speaking on condition of anonymity, noted the extradition process can be slow, as Turkey has expressed frustration that Washington has not yet sent back the preacher who has residency in the US.
The US is expected to send several State Department and Justice Department experts to help Turkey with the extradition request before Biden comes.
The US has also regularly dismissed conspiracy theories circulating in pro-government media outlets in Turkey that Washington had anything to do with the coup plan.
Turkish Prime Minister Binali Yildirim, speaking with reporters in Istanbul, describe the relationship with the US at the moment as "moderate" but reasserted the US remains a "strategic partner."
Yildirim and the US official both said Gulen was expected to dominate Biden's visit. Since 2013 the government has accused the preacher of running a "parallel state" and seeking to overthrow Erdogan.
Critics of the government note that Erdogan allowed Gulen's followers to gain footholds in the state bureaucracy, using them to its advantage. Since the coup attempt, Turkey has suspended or fired more than 80,000 civil servants and arrested 20,000 people.
The US and Turkey will also discuss the situation in Syria, where the US is backing Kurdish-led forces in the war against Islamic State.
Turkey is wary of Kurdish gains, fearing it could stoke nationalist sentiment among its own Kurdish minority and has often been reluctant to support US efforts in Syria to curtail the extremist group.
Yildirim also told reporters Turkey was opposed to dividing neighbouring Syria along ethnic lines.
Biden's visit comes as Erdogan recently went to Russia to mend ties with Moscow, his first trip abroad since the coup. Ankara officials say there is no plan for NATO member Turkey to pivot away from the West.