The former White House Covid response coordinator, Deborah Birx, has decried the press conference in 2020 during which, in her presence, Donald Trump floated the idea of the injection of disinfectant to treat coronavirus – calling the episode a “tragedy on many levels”.

In an interview with Good Morning America, Birx said she does not regret taking on the role in Trump’s team, even though she received criticism for not standing up to his misinformed comments more forcefully at the time.

Birx is promoting her new book, Silent Invasion: The Untold Story of the Trump Administration, Covid-19, and Preventing the Next Pandemic Before It’s Too Late, which is released on Tuesday.

When asked how she felt during the moment Trump promoted the use of disinfectants to treat the virus, Birx said: “At the beginning, I didn’t even know what was happening.” She said scientists and Trump had a discussion before the press conference about a study on how light and disinfectants could help kill the virus on outer surfaces.

She writes in her book that when Trump looked at her as he was talking about the subject, while she sat to the side, she had wanted to fall through the floor.

“This was a tragedy on many levels,” she told GMA host George Stephanopoulos.

She continued: “I didn’t realize … that scientists went into the Oval Office and they started that discussion there, and they continued it in front of America.”

Birx went on to explain that she spoke to Trump’s staff members immediately after the press conference, telling them that his statement was incorrect and had to be reversed.

“Many people don’t know me, but I’m a pretty direct person, so I immediately went to his most senior staff and to Olivia Troye [a former aide to the White House coronavirus taskforce] and said: this has to be reversed. And by the next morning the president was saying this [what he had said] was a joke.”

Birx was widely criticized for not flatly and emphatically contradicting Trump on the spot to the public, as he not only mused on the very dangerous concept of ingesting bleach to cure Covid, but also downplayed the virus and predicted that it would disappear.

Birx also revealed that she had a “pact” with “all the doctors in the doctors’ group,” including Anthony Fauci, Robert Redfield and Stephen Hahn, all of whom were on Trump’s Covid taskforce.

“It was if any one of the individuals were under so much pressure and they were fired, that we would all leave together from the taskforce,” she said, adding, “I think that was really important, because I really wanted to protect Bob Redfield and Steve Hahn and they were under enormous pressure.”