The intelligence organisation Mensa has offered to stage an IQ test for Donald Trump and Rex Tillerson after the president suggested that his IQ would be higher.

It came after it was reported that Tillerson may have called Trump a "f*****g moron", which he never denied saying.

But to help settle the score, as suggested by President Trump, Mensa has stepped up and offered to test the pair to determine who has the higher IQ.

Charles Brown, communications director for the organisation said: "American Mensa would be happy to hold a testing session for President Trump and Secretary Tillerson."

He also said that previous presidents may have attempted to enter the group, but could only confirm if they were successful.

Brown said: "It's important to note that our admissions test is not the sole way to qualify for Mensa, there are hundreds of other prior-evidence tests that can qualify a member. And, the early success of many presidents no doubt exposed them to those types of qualifying avenues."

The organisation is a selective group which requires an IQ score within the top 2% of the general population to gain access.

In an interview with Forbes, Trump hit back at the claims that Tillerson may have used the foul language against him saying: "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."

Last week, NBC revealed that the secretary of state used expletive-laden language to describe the president and was considering his position.

In a last-minute press conference, Tillerson denied that he ever considered quitting his post, but when asked about the "moron" comments, he simply described the question as "petty".

Speaking on Saturday 7 October, amid growing tensions between the state department and the White House, Trump said: "We have a very good relationship. 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."

It isn't the first time that Trump's IQ has been centre stage, in 2013, he tweeted that people shouldn't feel insecure about his brain power saying: "Sorry losers and haters, but my I.Q. is one of the highest - and you all know it! Please don't feel so stupid or insecure, it's not your fault."

Tillerson and Trump
U.S. President Donald Trump talks with Secretary of State Rex Tillerson during a meeting with members of his Cabinet at the White House in Washington, U.S., June 12, 2017.REUTERS/Kevin Lamarque