Turkish Foreign Minister Mevlut Cavusoglu says Washington is making efforts to extradite a US-based Muslim cleric accused of orchestrating a failed Turkish coup in 2016, the Reuters news agency and Turkish media reported on Sunday.

Cavusoglu cited comments apparently made by US President Donald Trump to his Turkish counterpart on the sidelines of the G20 summit in Argentina earlier this month.

Turkey has long sought the extradition of Fethullah Gulen, a one-time ally of Turkish President Recep Tayyip Erdogan, who is blamed by Turkish authorities for the failed putsch when rogue soldiers commandeered tanks and helicopters, attacked parliament and shot unarmed civilians.

Read more: Turkey seeks extradition of 84 Gulen supporters from US

Gulen, who lives in the US state of Pennsylvania, has repeatedly denied any involvement.

New attempt to seize Gulen finances

Erdogan said last week he would advance plans to target the overseas financing of Gulen supporters.

Cavusoglu, meanwhile, told a conference in Doha he had "recently seen a credible probe by the FBI on how the Gulen organization avoids taxes."

The extradition request has been a major cause of friction between the two leaders, and rumors surfaced last month that the White House had made inquiries about the legal implication of expelling Gulen.

That forced Trump to deny he was considering extraditing the preacher as part of a deal with the Ankara government to ease political pressure over the killing of Saudi journalist Jamal Khashoggi in Istanbul.

Since the coup attempt, the Turkish government launched a massive purge on those with alleged links to Gulen's movement. Around 218,000 people were subsequently arrested, some 50,000 jailed, and 140,000 civil service workers dismissed.

Read more: Turkey lifts state of emergency, but fear of repression lingers

Erdogan has been strongly criticized for cracking down on dissent as part of a more comprehensive power grab.

Human rights campaigners have meanwhile expressed doubts over whether Gulen would receive a fair trial in Turkey.

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