Washington DC: On Tuesday (October 6) US’ top infectious diseases expert Dr Anthony Fauci, whose advocacy of public health guidelines to fight the coronavirus has conflicted with President Donald Trump's downplaying of the pandemic, said the recent rash of infections at the White House could have been prevented.

Since the Republican President announced on Friday (October 2) that he and first lady Melania Trump had contracted the virus, several close aides to Trump and senior Republican politicians have tested positive for the coronavirus.

"Take a look at what happened this week at the White House," Fauci said in an interview with American University's Kennedy Political Union, when asked what advice he had about how people could discuss preventive actions with relatives who believed the pandemic was a hoax.

"That is a reality, right there. And every day that goes by more people are popping up that are infected. It's not a hoax. It's an unfortunate situation when you see something like that because that could have been prevented," Fauci said.

Fauci has been a long-time advocate of wearing face masks to prevent the spread of coronavirus.

Trump returned to the White House on Monday (October 5) from a military hospital where he spent three nights being treated for Covid-19, telling Americans "to get out there" and not let their lives be dominated by the virus.

He left hospital wearing a mask but removed it to pose for pictures on the White House balcony and did not put it back on when he entered the building.

The President, who is trailing his Democratic rival Joe Biden ahead of the November 3 election, has pushed for quicker reopening of the economy and schools and accused Democrats of preventing that for political purposes.

Trump rarely wears a mask in public, and there is often little social distancing at his campaign rallies and White House events.

Fauci, director of the National Institute of Allergy and Infectious Diseases, has ascribed a surge in coronavirus infection in part to the country's failure to shut down completely.

More than 210,000 people in the United States have been killed by the coronavirus and more than 7 million infected, more than any other country.

White House senior adviser Stephen Miller, a top speechwriter for Trump and an influential adviser on Trump's hardline immigration policy, on Tuesday became the latest Covid case reported among Trump associates.

Others announcing they had tested positive in recent days include close Trump adviser Hope Hicks; White House spokeswoman Kayleigh McEnany; Trump's campaign manager Bill Stepien; and Republican Senators Mike Lee, Thom Tillis and Ron Johnson.