WASHINGTON - Deborah Birx, the White House coronavirus response coordinator under President Donald Trump, said most coronavirus deaths in the United States could have been prevented if the Trump administration had acted earlier and more decisively. 

Birx made her comments in the CNN documentary "Covid War: The Pandemic Doctors Speak Out," a clip from which the network released Saturday. The full documentary will air 9 p.m. Sunday.

In it, CNN chief medical correspondent Sanjay Gupta asked Birx how much of a difference she thinks it would have made had the United States "mitigated earlier, ... paused earlier and actually done it," referring to extending shutdowns, urging people to wear masks and implementing other steps to slow the spread of the virus.

"I look at it this way: The first time, we have an excuse. There were about 100,000 deaths that came from that original surge," Birx told Gupta. "All of the rest of them, in my mind, could have been mitigated or decreased substantially."

Since last February, more than 549,000 people in the United States have died of the coronavirus. The initial rise in cases in spring 2020 was followed by another spike that summer, then a post-holiday surge over the winter that led to the deadliest month for the country so far, when an average of 3,100 people died every day of covid-19 in January.

Trump, who later admitted that he initially tried to downplay the seriousness of the virus, at first compared it to the flu and suggested the media was in "hysteria mode."

The World Health Organization declared the coronavirus outbreak a pandemic on March 11, 2020, and Trump declared a national emergency two days later. In mid- to late March, several states announced stay-at-home orders for nonessential workers in an effort to contain the spread of the virus.

By April and May, however, Trump had pushed for cities and states to reopen, and he falsely suggested that the virus could not survive in the sun and that "tremendous" light could kill it off. He also began hyping hydroxychloroquine as an unproven treatment, continued referring to the virus as the "China virus" and questioned the effectiveness of wearing face masks.

Birx, who headed the White House's efforts to combat the coronavirus throughout that period, has been criticized for not speaking more frequently and more forcefully against Trump. Last March, Birx praised Trump for being "so attentive to the scientific literature and the details and the data" with regards to the outbreak.

As The Washington Post's Philip Bump reported, Birx had presented overly optimistic data several times:

We documented such statements on March 27 (the day she praised Trump's reliance on data), April 6 and April 16. A claim such as stating that there was a "low level of cases" in 40% of the country because 19 states had few cases is clearly misleading, for example, given that those 19 states represented only 7% of the country's population.

Birx also sat quietly at a news conference last July when Trump pondered whether people could be injected with disinfectant to "knock out" the coronavirus. Months later, she described it as an "extraordinarily uncomfortable" moment that she still thought about daily.

"Those who have served in the military know there are discussions you have in private with your commanding officers and there are discussions you have in public," Birx told ABC News's Terry Moran earlier this month.

In January, Birx defended her actions, telling CBS News that the White House "censored" her and that she had "always" considered quitting.

On Saturday, much as with the other times Birx has spoken out since Trump left office, her comments were met with frustration from Democrats.

"The malicious incompetence that resulted in hundreds of thousands of unnecessary deaths starts at the top, with the former President and his enablers," Rep. Ted Lieu, D-Calif., tweeted. "And who was one of his enablers? Dr. Birx, who was afraid to challenge his unscientific rhetoric and wrongfully praised him."

The CNN documentary will also feature interviews with five other doctors at the center of the coronavirus response, including Anthony S. Fauci from the National Institute of Allergy and Infectious Diseases; Stephen Hahn from the Food and Drug Administration; and Robert Redfield from the Centers for Disease Control and Prevention.