Biden tells Turkey's Erdogan: only a federal court can extradite Gulen

In statements to reporters in Ankara after meeting Erdogan, Biden said those involved in the coup attempt were terrorists and said the U.S. had more lawyers working on the request for Gulen's extradition than in any other such recent case.

Biden said it may be difficult for Turks to understand that President Barack Obama had no constitutional authority to extradite the cleric. He promised that Washington would work closely with the Turkish government on the case.

(Reporting by Jeff Mason; Writing by Nick Tattersall; Editing by Patrick Markey)