Former US president Donald Trump on Monday lashed out at two of the country's leading figures in the coronavirus battle after they criticized his handling of the pandemic.

In an angry statement, Trump described Anthony Fauci and Deborah Birx as "two self-promoters trying to reinvent history to cover for their bad instincts and faulty recommendations, which I fortunately almost always overturned."

Trump accused Fauci, who leads the National Institute of Allergy and Infectious Disease, of trying to take credit for vaccine development, and "moving the goalposts to make himself look as good as possible."

The former president added that Birx, who was his coronavirus task force coordinator, was "a proven liar with very little credibility left."

The bitter outburst came after Fauci told CNN how shocked he had been when Trump last April called for states to "liberate" themselves as experts pleaded with Americans to obey shutdown orders.

Birx said in an interview that -- while working at the White House -- she had received a "very uncomfortable" phone call from Trump after speaking publicly about the rapid spread of COVID-19.

She also said "the federal government did not provide consistent messaging to the American people and that is fault number one."

The interviews with Fauci and Birx were part of a CNN documentary on the pandemic.

Birx retired after a bruising time at the White House that tarnished her once stellar reputation.

Fauci, 80, is now the White House's top pandemic advisor under President Joe Biden after Trump's election defeat.

"Dr. Fauci and Dr. Birx moved far too slowly, and if it were up to them we'd currently be locked in our basements as our country suffered through a financial depression," Trump said.

He also attacked Fauci's ability to throw a baseball, described him as "king of the flip-flops," and said "Birx was a terrible medical advisor, which is why I seldom followed her advice."

Trump, who makes a habit of strong counter-attacks to any criticism, has kept a relatively low profile since leaving the White House and moving to his Mar-a-Lago resort in Florida.

Under Trump, the number of COVID-19 deaths in the United States soared to by far the world's highest toll as he resisted face masks, shutdowns and other measures to contain the pandemic.

Biden has quickly ramped up vaccine distribution but also warned that the pandemic, which has killed 549,000 people in the US, remains a major threat as data shows another potential surge in infections.