Donald Trump. Getty/Pool President Donald Trump has weighed in again on an NBC News report that Secretary of State Rex Tillerson called him a "moron" over the summer.

In an interview with Forbes published Tuesday, Trump dismissed the story as false — and offered a solution.

"I think it's fake news," Trump said of the reported quip. "But if he did that, I guess we'll have to compare IQ tests."

"And I can tell you who is going to win," Trump said.

NBC News said Tillerson called Trump the name followed a meeting on Afghanistan in which Trump compared "the decision-making process on troop levels to the renovation of a high-end New York restaurant." Also around that time, Trump made a politicized speech to the Boy Scouts of America, which Tillerson once led.

In the Forbes interview, Trump also addressed his undercutting Tillerson's reported negotiations with North Korea.

"He was wasting his time," Trump said. "I'm not undermining — I think I'm actually strengthening authority."

Trump has consistently maintained throughout his public life that his "IQ is one of the highest," but his political opponents have frequently taken to deriding his ideas and mental well-being.

Most recently, Republican Sen. Bob Corker compared the Trump White House to an "adult day care center" in which aides constantly work to keep Trump from bumbling, possibly into "World War III."