US President Donald Trump dances during a rally at Prescott Regional Airport in Prescott, Arizona on Tuesday. Photo: AFP

US President Donald Trump went after top government scientist Anthony Fauci in a call with campaign staffers on Monday, suggesting the hugely respected and popular doctor was an "idiot." 

Fauci, a key member of the White House coronavirus task force, has increasingly become a focus for the president's frustration as he bids to shape the messaging on the much-criticized federal response to the pandemic.

"People are tired of COVID[-19]," Trump told his campaign team in a call on which several members of the press were present. 

"People are saying, 'Whatever - just leave us alone.' They're tired of it. People are tired of hearing Fauci and all these idiots," the president said, according to several US media outlets. 

"He's been here for, like, 500 years," Trump complained of the 79-year-old Fauci, who is recognized worldwide for his work directing the National Institute of Allergies and Infectious Diseases in suburban Washington DC. 

"Fauci, if we listened to him, we'd have 700,000 [or] 800,000 deaths," Trump claimed on the call, before saying that it would be counterproductive to fire him before the November 3 election. 

The president's latest attack seemed to garner a defense of the doctor from Republican Senator Lamar Alexander. 

"Dr Fauci is one of our country's most distinguished public servants. He has served 6 presidents, starting with Ronald Reagan," Alexander tweeted.

"If more Americans paid attention to his advice, we'd have fewer cases of COVID-19, and it would be safer to go back to school and back to work and out to eat."

Trump's remarks came a week after Fauci expressed displeasure at the use of a clip of him in a Trump campaign video about coronavirus. 

"In my nearly five decades of public service, I have never publicly endorsed any political candidate," the immunologist hit back, saying his statements in the video were taken out of context. 

At various points during the pandemic response, Fauci has clarified or corrected Trump's public comments on the development of COVID-19 treatments and vaccines.

AFP