Story highlights Erdogan: US will soon have to make a choice between Turkey and Gulen

Demand comes after Turkish and Russian leaders meet in Moscow

(CNN) Turkish President Recep Tayyip Erdogan appeared to give the United States an ultimatum, demanding the extradition of a cleric he believes is behind the failed July 15 coup attempt.

Erdogan said the US would eventually have to choose between its relationship with Turkey and Fethullah Gulen, a former Erdogan ally who has been in self-imposed exile in Pennsylvania since 1999, the state-run Anadolu news agency reported Wednesday.

"Sooner or later the US will make a choice. Either Turkey or FETO," Erdogan said, in reference to the movement headed by Gulen.

Turkey has requested Gulen's extradition, with a delegation of parliamentarians handing over dozens of boxes of documents to US officials to support its case.

President Obama has said that the cleric would only be extradited as a result of "a legal process," and if the extradition request is found to be justified according to the relevant laws and treaties.