U.S. Vice President Joe Biden says the White House is determined to listen to "every scrap of evidence" Turkey provides before deciding if it will extradite Muslim cleric Fethullah Gulen.
Gulen lives in the eastern state of Pennsylvania, and Turkey is demanding his immediate extradition, accusing him of organizing last month's failed military coup -- a charge he denies.
Biden met in Ankara Wednesday with Turkish President Recep Tayyip Erdogan. He tried to head off Erdogan's impatience by explaining that American courts require firm evidence before a suspect is surrendered to another country.
"You can't go into the court and say, 'This is a bad guy'... you have to say 'this is a guy or woman who committed the following explicit crime,'" Biden said.
He said prosecutors need to show a judge probable cause, and that sometimes courts move slowly. Biden noted that President Barack Obama could be impeached if he orders a foreign national extradited without a proper hearing.
Turkish Prime Minister Binali Yildirim has said any delay in sending Gulen back to Turkey could harm U.S.-Turkish relations.
Biden said he understands Turkey's anger, and said the U.S. has no interest in protecting anyone who has done anything to hurt one of its allies.
Turkey has arrested or fired 80,000 government workers, judges and academics it believes are Gulen supporters or were involved in the coup attempt launched by a group of renegade military officers.