Speaking to Forbes magazine, President Donald Trump still calls it “fake news” to say his secretary of State called him a “moron.” But argues he has a way to settle it if Rex Tillerson did make the jab.

Trump who often boasts about his intelligence and achievements said: “I think it’s fake news. But if he did that, I guess we’ll have to compare IQ tests. And I can tell you who is going to win.”

Tensions between Trump and Tillerson appeared to escalate last week when NBC News reported that VP Mike Pence had to persuade Tillerson from resigning in the summer, and also alleged the Secretary of State to have called the president a “moron” following a July meeting with members of the president’s national security team and Cabinet.

In a quickly scheduled news conference shortly after the report, Tillerson said he never considered leaving his job but did not deny calling the president the derogatory name..

He said he wouldn’t dignify “petty nonsense” and insisted he remained committed to the administration’s foreign policy goals. But a State Department’s spokeswoman later said he never used such Language.

However, despite the remarks, Trump told reporters on Tuesday that he still has confidence in Tillerson, insisting “I didn’t undercut anybody” with the IQ test comment.

“I’m not undermining… I think I’m actually strengthening authority,” he said.

But the President’s frequent intervention in Tillerson’s jurisdiction casts further doubts on his trust in the former oil executive.

Apart from publicly underscoring Tillerson’s diplomatic efforts on North Korea, Trump recently overlooked a traditional State Department’s area of influence by giving his son-in-law Jared Kushner the task of leading the administration’s efforts towards a Middle East peace deal.

But, in the midst of it all, the pair are scheduled for a dinner in the White House later Tuesday alongside Defense Secretary Jim Mattis.