New York City Mayor Bill de Blasio said Monday he was “very comfortable” meeting with federal corruption prosecutors Friday looking into his campaign fundraising operation.

In his first interview since talking with investigators from the U.S. attorney’s office, de Blasio told cable network NY1 the four-hour meeting signaled his willingness to “cooperate” with authorities as they reportedly investigate allegations that contributors to his first mayoral campaign were given preferential treatment by City Hall officials.

“I want to emphasize from the beginning, when the investigation began, we said ‘I want to cooperate. My team’s going to cooperate in every way. We want to provide all the information the U.S. attorney needs,’ ” de Blasio told NY1 Political Reporter Errol Lewis, during his weekly “Mondays with the Mayor” segment.

De Blasio, who is seeking re-election this year, said he was unsure when U.S. Attorney Preet Bharara’s office will wrap up its investigation. Federal prosecutors are examining whether de Blasio or his aides doled out favors to donors, including intervening on behalf of Long Island restaurateur Harendra Singh in a lease dispute over a restaurant property he formerly leased from the city.

Singh was indicted last year in a corruption case involving Nassau County Executive Edward Mangano, and has been negotiating cooperation deals with investigators on Long Island and in Manhattan.

De Blasio maintained in the cable TV interview Monday that he and his aides have “done everything appropriately.”

“We’ve held ourselves to high ethical standards,” he said.

The mayor is scheduled to deliver a speech in lower Manhattan Tuesday outlining his plans to combat city homelessness.

“This is a long war,” the mayor said when asked about the homeless problem. “We’re going to be at this a long, long time.”