Turkey blames the failed coup on Fethullah Gulen, a cleric based in the United States who has a wide following in Turkey and denies any involvement.
On 18 July Ankara demanded Washington hand him over. Washington says it is prepared to extradite him but only if Turkey provides evidence linking him to crime. Yildirim rejected that demand.
"We would be disappointed if our (American) friends told us to present proof even though members of the assassin organization are trying to destroy an elected government under the directions of that person," Yildirim said.
"At this stage there could even be a questioning of our friendship," Yildirim added.
Yildirim said 232 people were killed in Friday night's violence, 208 of them civilians, police and loyalist soldiers, and a further 24 coup plotters. Officials previously said the overall death toll was more than 290.