The White House says US President Donald Trump was joking when he appeared to question his Secretary of State's intelligence.
Trump said in an interview published in Forbes magazine that if Rex Tillerson did call him a moron, as has been reported, the two should "compare IQ tests."
"And I can tell you who is going to win," Trump added.
White House Press Secretary Sarah Huckabee Sanders told reporters that the president "never implied that the Secretary of State was not incredibly intelligent."
She says: "He made a joke, no more than that."
She also says the president has "100 percent confidence" in Tillerson.
She said reporters "should get a sense of humour."
Sanders also commented on the growing spat between Trump and Tennessee Sen. Bob Corker.
Corker has said that Trump is threatening to start World War III with his rhetoric toward North Korea.
Sanders said "Senator Corker is certainly entitled to his own opinion but he's not entitled to his own facts."
She added that Trump, has been an "incredibly strong leader on foreign policy and national security."