US officials are reviewing evidence that Turkey has provided about Muslim cleric Fethullah Gulen, who has been blamed by Turkey for a failed coup there in July, the White House said on Wednesday.

Ankara has demanded that Gulen be extradited to Turkey from the United States.

"Turkey has longstanding concerns with Mr. Gulen's activity, and they have presented significant evidence to the United States, and Department of Justice officials are carefully reviewing that evidence," White House spokesman Josh Earnest said in a news briefing.