Islamic cleric Fethullah Gulen speaks to members of the media at his compound last month in Saylorsburg, Pa. (Chris Post/AP)

Turkey’s request for U.S. extradition of self-exiled cleric Fethullah Gulen refers only to his alleged activities before last month’s failed coup attempt, for which the Turks have not yet provided any evidence of his involvement, a senior administration official said.

“It’s actually tied to allegations of certain alleged criminal activities that pre-date the coup,” the official said of the request now being examined by the Justice Department. “At this point, Turkish authorities have not put forward a formal extradition request based on evidence that he was involved in the coup” attempt.

Turkey has blamed Gulen’s followers for orchestrating the attempted toppling of the government, and has arrested tens of thousands of alleged sympathizers in purges of the military, the judiciary and the media, even as it has closed down hundreds of schools and business enterprises operated by alleged Gulen backers. Gulen, who lives in Pennsylvania, is a permanent U.S. resident.

[He’s 77, frail and lives in Pennsylvania. Turkey says he’s a coup mastermind.]

Amid rising bilateral tensions, Turkey has said that its future relationship with the United States will be influenced by the outcome of the extradition request. Turkey, in addition to its membership in NATO, is a key U.S. ally in the fight against the Islamic State.

“Sooner or later, the U.S. will make a choice. Either Turkey or FETO,” Turkish President Recep Tayyip Erdogan said last week, referring to Gulen. He said he assumed the United States would “send him back.”

Turkish media and some government officials have suggested that the United States backed the coup attempt, which the Obama administration has sharply denied.

U.S. officials, beginning with President Obama, have said that they have no control over the extradition process. “Professional experts at the Department of Justice are looking over” the information provided by Turkey, said the senior administration official, who spoke on the White House-imposed condition of anonymity.

The official, who briefed reporters on a trip that Vice President Biden will make to Turkey next week, said that U.S. officials are “working alongside their Turkish counterparts to make sure we understand” everything contained in the evidence, and a Justice team will travel to Turkey “in the coming days.”

“If there is probable cause for extradition,” the official said, “ultimately a court will determine whether the evidence is sufficient. . . . We are still a ways down the line from even knowing whether that’s possible.” Officials have said that even if the Justice Department decides extradition is warranted, a court case and possible appeals could take years.

Asked what message Biden would impart to Erdogan, the official said he would “remind the Turkish people that the United States came out emphatically and immediately condemned” the coup attempt.

“I know that there has been some allegations and conspiracy theories” in Turkey of U.S. involvement, said the official, who called such talk “unhelpful.”

“As the vice president would say, all of that’s malarkey, and I think we’ll make that clear during the meetings and during engagements with the Turkish people.”