Turkey is taking the FBI's investigation into the Gülenist Terror Group (FETÖ) seriously, Foreign Minister Mevlüt Çavuşoğlu said Tuesday.

Speaking to reporters in Ankara, Çavuşoğlu added that Turkey is continuing to negotiate with the U.S. the extradition of FETÖ members.

He said Turkey has delivered a list of 84 FETÖ suspects who reside in the U.S., to the Secretary of State Mike Pompeo and National Security Advisor John Bolton.

"As the Justice Ministry informs us over the additional information and evidence, [these new materials] are being delivered to our addressees," Çavuşoğlu said, underlining that there are finally some concrete decisions on the matter.

"During my visit to New York, our citizens told me that in a FETÖ 'imam' in southern New Jersey was arrested as part of the FBI investigation," he said, adding that both countries were sharing information on the matter.

FETÖ staged the July 15, 2016 coup attempt to overthrow Turkey's democratically elected government. The attempt killed 251 people and wounded more than 2,200.

The terrorist group is also accused of using its infiltrators in the police and the judiciary to launch two other coup attempts on Dec. 17 and Dec. 25, 2013, under the guise of graft probes. It also launched sham trials against its adversaries using forged evidence and trumped-up charges.

The U.S. remains the main hub of FETÖ activity, where the shadowy group operates hundreds of charter schools and affiliated companies, providing visa and employment opportunities to thousands of its followers.

The group's Leader Fetullah Gülen has lived in self-imposed exile in a secluded compound in the U.S. state of Pennsylvania since 1999.

Last week, Çavuşoğlu announced that the FBI was investigating FETÖ's network in 15 U.S. states and has already made arrests in New Jersey.

"The FBI informed us that they have begun to see the dark side of FETÖ through their findings," he said.