Dr. Scott Atlas has resigned as special adviser to President Donald Trump on the coronavirus, according to a White House official, after a controversial four months at the White House in which he clashed repeatedly with other members of the task force responding to the deadly pandemic.

Atlas' exit was first reported by Fox News, which obtained his resignation letter.

"I worked hard with a singular focus – to save lives and help Americans through this pandemic," Atlas wrote in the letter, according to Fox News.

"As time went on, like all scientists and health policy scholars, I learned new information and synthesized the latest data from around the world, all in an effort to provide you with the best information to serve the greater public good," he wrote. "But, perhaps more than anything, my advice was always focused on minimizing all the harms from both the pandemic and the structural policies themselves, especially to the working class and the poor."

Atlas, a neuroradiologist with no background in infectious diseases, has faced scrutiny for downplaying the importance of face masks and his reported views on "herd immunity," an approach that holds that once enough individuals have been infected and become immune, others are less likely to be infected.

The top U.S. infectious diseases expert, Anthony Fauci, told CNN in September he was concerned that information given by Atlas – a late addition to the White House coronavirus task force – was "really taken either out of context or actually incorrect."

He once again distanced himself from Atlas earlier this month. "I don't want to say anything against Dr. Atlas as a person, but I totally disagree with the stand he takes. I just do, period," Fauci said in an interview on NBC.

Robert Redfield, director of the U.S. Centers for Disease Control and Prevention, raised similar concerns during Atlas' time in office.

"Everything he says is false," Redfield was quoted as saying during a telephone call while on a plane from Atlanta to Washington, NBC reported in September.

(With input from Reuters)