"What they're doing is they're gaming the system so that when I go into the debate, I'm going to be treated very, very unfairly by the moderators," Trump said.

He argued that the perception that Lauer was "soft on Trump" was being promoted so the next Clinton-Trump moderator will try to be "really hard on Trump."

The comments from Trump come as he and Clinton battle the media for favorable coverage.

Clinton surrogates said the Lauer interview highlights a pattern in coverage in which Trump gets softer questions than Clinton, who was grilled by the NBC host over her private email server.

Trump and his supporters argue the media is firmly on Clinton's side, as evidenced most recently in criticism of questions raised by conservatives about Clinton's health.

Trump has feuded with past debate moderators, most notably Fox News anchor Megyn Kelly in the first GOP debate.

Trump on Monday likened what he said he sees happening with the debates to how famed Indiana college basketball coach Bobby Knight, a backer of Trump, used to handle referees.

"Bobby would do numbers on the referee and toward the end of the game they would just sort of subconsciously give him the call," Trump said. "They're doing the same thing now."

The first of three presidential debates is scheduled for Sept. 26 in New York. It will be the first time Trump and Clinton appear on stage together, after their consecutive appearances at the forum last week.