Fox News obtained the resignation letter dated Dec 1 for Scott Atlas, who lacked relevant experience or qualifications in public health or infectious disease.

The outlet also reported that Atlas’s contract was already set to expire later this week.

“I am writing to resign from my position as special advisor to the president of the US,” Atlas said in his resignation letter.

He thanked Trump for the honour and wished “all the best” to president-elect Joe Biden’s incoming administration.

“I worked hard with a singular focus – to save lives and help Americans through this pandemic,” Atlas said, adding that he “always relied on the latest science and evidence, without any political consideration or influence”.

Atlas attracted controversy during much of his time working for the outgoing president, and his resignation comes with Covid-19 cases surging nationwide.

Both the scientific and public health community heavily disputed his expertise and qualifications for his role.

In October, he tweeted: “Masks work? NO,” despite overwhelming scientific evidence proving the benefit of wearing masks. Twitter concealed the message as misinformation.

He also gave an interview to Russian state-controlled TV channel RT, during which he downplayed the severity of the US Covid-19 spread.

In November, he urged people in Michigan to “rise up” against Covid-19 measures, such as lockdowns to slow the spread of the virus, rather than engage in an all-hands-on-deck effort to defeat the pandemic.

As of Monday evening, the US had recorded 13,522,247 Covid-19 cases and 267,844 deaths, both by far the worst tolls in the world.