Dr. Anthony Fauci, the chief medical adviser to President Biden, has faced harsh criticism from Republicans on what they see as a reversal on COVID stances over the last year. 

The heat turned up and took off with renewed intensity this week following the release of thousands of emails obtained through Freedom of Information Act (FOIA) requests, revealing the top doctor’s communications from the early stages of the pandemic.

FAUCI CLAIMS US GAVE $600,000 TO WUHAN LAB RESEARCH; DOCUMENTS SHOW IT WAS MORE

For several weeks following the outbreak of coronavirus in the U.S., the infectious disease specialist said that wearing masks was unnecessary unless someone was already infected with the deadly virus. 

In a Feb. 5, 2020, email exchange, Fauci told former Health and Human Services (HHS) Secretary Sylvia Burwell that a mask was unnecessary during her then-upcoming trip. 

"Masks are really for infected people to prevent them from spreading infection to people who are not infected rather than protecting uninfected people from acquiring infection," Fauci wrote in an email obtained by Buzzfeed News

But Fauci and other top health officials reversed their stance as the virus took off. He admitted in a June 2020 interview with The Street that people were initially advised not to wear masks to preserve the limited supply for health care workers and that masks "can protect you to a certain degree."

When asked why Americans were not told to wear masks from the beginning, he said:

"The reason for that is that we were concerned the public health community, and many people were saying this, were concerned that it was at a time when personal protective equipment, including the N95 masks and the surgical masks, were in very short supply," he said. "And we wanted to make sure that the people namely, the health care workers, who were brave enough to put themselves in a harm way, to take care of people who you know were infected with the coronavirus and the danger of them getting infected."

Fauci has also found himself in hot water over what some see as a disregard for the origin of the virus.   

Emails received as early as January 2020 urged the director of the National Institute for Allergy and Infectious Diseases (NIAID) to consider the possibility that the pandemic was not the result of a virus-jumping species, but rather a lab leak.

Fauci argued that the science at the time did not support such a theory.

An email from EcoHealth Alliance head Dr. Peter Daszak – the nonprofit that helped fund research at the Wuhan Institute of Virology (WIV) – was released this week, thanking Fauci for his rejection of the lab-leak theory. 

WALL STREET JOURNAL EDITORIAL: 'REASONABLE TO ASK' WHY FAUCI WAS SLOW TO ACCEPT CORONAVIRUS LAB-LEAK THEORY

"I just wanted to say a personal thank you on behalf of our staff and collaborators, for publicly standing up and stating that the scientific evidence supports a natural origin for COVID-19 from a bat-to-human spillover, not a lab release from the Wuhan Institute of Virology," Daszak wrote to Fauci at the time.

Fox News could not reach Fauci for comment, but in an interview on CNN’s "New Day" Thursday he said: "You can misconstrue it however you want – that email was from a person to me saying 'thank you' for whatever it is he thought I said, and I said that I think the most likely origin is a jumping of species. I still do think it is, at the same time as I'm keeping an open mind that it might be a lab leak."

The email sparked outrage and prompted Sen. Rand Paul, R-Ky., to say "Told you," in a tweet, adding: "Can’t wait to see the media try to spin the Fauci FOIA emails."

Sen. Josh Hawley, R-Mo., called for Fauci to be removed from his post and for a Congressional inquiry into the origins of the virus. 

"Anthony Fauci’s recently released emails and investigative reporting about #COVID19 origins are shocking," Hawley tweeted Friday. "The time has come for Fauci to resign and for a full congressional investigation into the origins of #COVID19 - and into any and all efforts to prevent a full accounting." 

"And Congress must also find out to what extent Fauci’s NIAID was involved in financing research at the Wuhan Institute of Virology," he added. 

Hawley’s demands preceded reporting by Fox News Friday that revealed the NIAID granted more $826,000 to fund research on "Understanding the Risk of Bat Coronavirus Emergence" over a six-year period. 

Fauci had previously informed lawmakers the National Institutes of Health (NIH) – which encompasses the NIAID – provided $600,000 to the Wuhan lab over a five-year period. 

The White House did not respond to Fox News’ questions, but President Biden backed his chief medical advisor Friday, telling reporters he is "very confident in Dr. Fauci."

CLICK HERE TO GET THE FOX NEWS APP

White House press secretary Jen Psaki said there is no circumstance where she could imagine Fauci being fired by the president.