Mr Trump is accused of telling a news reporter COVID-19 is “deadly stuff” during a conversation on February 7. The conversation is detailed in a book titled Rage.
Written by investigative journalist Bob Woodward, it details Mr Trump’s presidency and is set for release on Tuesday.
CNN has obtained a copy of the book before its release and detailed how in it Mr Trump told Woodward coronavirus is "more deadly than even your strenuous flus” but chose to downplay it.
The comments are in contrast to what Mr Trump was telling people in the US at the time.
On February 26, he said the US’s 15 cases would soon be zero.
"It's going to disappear. One day it's like a miracle, it will disappear," he told reporters on February 27.
He also repeatedly referred to the virus as being less dangerous than the common flu despite conversations with Woodward in which he said it was far more lethal.
Many people at the time called for Mr Trump to take the virus seriously and to introduce lockdowns.
The US currently has almost 6.4 million cases of COVID-19 and more than 190,000 deaths, according to Johns Hopkins University data. It has more deaths and cases than any other country in the world.
Jonathan Karl, a journalist for the ABC, posed the question to Mr Trump on Thursday accusing him of lying.
"Why did you lie to the American people? And why should we trust what you have to say now?" Karl said.
The US President called the question a “disgrace”.
“I didn't lie. What I said is: 'We have to be calm; we can't be panicked’,” Mr Trump said.
"Your question — the way you phrased that is such a disgrace.
"It's a disgrace to ABC Television Network. It's a disgrace to your employer."
He later lashed out at Woodward too.
“Bob Woodward had my quotes for many months,” he tweeted.
“If he thought they were so bad or dangerous, why didn’t he immediately report them in an effort to save lives? Didn’t he have an obligation to do so? No, because he knew they were good and proper answers. Calm, no panic!”
Woodward was famously one of the reporters who broke stories on the Watergate scandal for The Washington Post.
He also published a book about Mr Trump’s presidency in 2018 titled: Fear.
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