WASHINGTON — President Donald Trump proposed an “IQ tests” face-off with Secretary of State Rex Tillerson after the nation’s top diplomat reportedly called the president a “moron” and disparaged his grasp on foreign policy.

In an interview with Forbes magazine published Tuesday, Trump fired a shot at Tillerson over the “moron” revelation, first reported by NBC News and confirmed by several other news organizations, including The Washington Post.

“I think it’s fake news,” Trump said, “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’s dare is the latest evidence of what White House officials have described as a breach of trust between the president and secretary of state.

Reporters asked Trump over the weekend about his relationship with Tillerson.

“We have a very good relationship,” Trump said on Saturday. “We disagree on a couple of things. Sometimes I’d like him to be a little bit tougher. But other than that, we have a very good relationship.”

In the Forbes interview, for the magazine’s cover under the headline “Inside Trump’s Head,” the president teases upcoming economic-development legislation “nobody knows about” that would penalize companies that move operations overseas and offer incentives for those that stay in the United States.

Trump previewed what he called “an economic-development bill, which I think will be fantastic. Which nobody knows about. Which you are hearing about for the first time.” The president said the policy is “both a carrot and a stick.”

Trump also told Forbes that he has purposefully not filled many jobs throughout the federal government, including at the State Department, where many of the top positions remain vacant.