As the president moved his focus away from locking down the nation to focusing on the economic recovery he has often clashed with Dr Fauci's insistence on combating the spread of the virus.
CNN first reported Fauci's displeasure with the campaign ad.
"We have a baseline of infections now that varies between 40 and 50,000 per day". The video is from a nationally broadcast television interview in which Dr Fauci was praising the work of the Trump administration.
"I, as one of many people on a team, I'm not the only person", Fauci said during an interview on Fox News' "Life, Liberty & Levin". The White House also tried to marginalize Fauci, excluding him from pandemic briefings.
Fauci added that he has been attempting to educate people-primarily younger adults-that the virus cannot only threaten their life, but the lives of others. "The use of my name and my words by the GOP campaign was done without my permission, and the actual words themselves were taken out of context, based on something that I said months ago regarding the entire effort of the task force".
"In my almost five decades of public service, I have never publicly endorsed any political candidate", Dr Fauci said in a statement on Sunday. AdvertisementIn the ad, Fauci said, "I can't imagine that anybody could be doing more", in terms of acting on the onset of the COVID-19 outbreaks in the U.S., but the line was in reference to the White House task force, not specifically Trump.
Tim Murtaugh, communications director for the Trump campaign, said, "These are Dr. Fauci's own words".
The Trump campaign defended the advert. "That's a bad place to be when you're going into the cooler weather of the fall". "We have done a "phenomenal" job, according to certain governors".
Asked what the consequences would be of not following such steps, Fauci replied: "I think we're facing a whole lot of trouble".
The dispute came as Trump declared he was ready to return to the campaign trail despite unanswered questions about his health on the eve of a Florida rally meant to kick off the home stretch before Election Day. Hundreds of people gathered on Saturday afternoon on the South Lawn for a Trump address on his support for law enforcement from a White House balcony.
Last month he was slammed for holding a large, indoor campaign rally in Nevada that violated the state's COVID-19 regulations and during which supporters were packed together - many without masks, McClatchy News previously reported.
"We're not talking about shutting down the country, but we're talking about prudent careful serious public health considerations, like wearing a mask, like avoiding congregate settings", Fauci said. "That's not very hard to do, and it should not interfere with getting the economy open again".