The White House on Tuesday defended President Biden's past rhetoric declaring the country had gained the upper hand over the coronavirus and touting vaccinated Americans no longer needed masks on the same day the Centers for Disease Control and Prevention (CDC) rolled out updated guidance that again recommends that those who have gotten the shot wear face coverings in certain settings.

Press secretary Jen Psaki faced a barrage of questions about Biden's past comments in which he expressed optimism the U.S. was in a strong position against the virus. She did not say the president regretted his rhetoric in hindsight but instead noted the delta variant has drastically changed the country's outlook as it battles an evolving threat.

"The role of the federal government and our public health officials is to continue to look at evolving data, evolving threats of a historic virus, provide that public health guidance to the American people to protect more people and save more lives. That's what they're doing," Psaki said.

Biden celebrated in May after the CDC announced vaccinated Americans could go without masks in public settings. The White House put out a video at the time of Biden saying that "it's vaxxed or masked," setting it up a binary choice between getting the shot or wearing a face covering.

On the Fourth of July, Biden took something of a victory lap, holding a large outdoor gathering at the White House and boasting the nation was "closer than ever to declaring our independence from a deadly virus."

Psaki argued the administration's message has been consistent that unvaccinated Americans have always been encouraged to wear masks and that getting a shot is the best way to prevent serious illness or death. Screens in Tuesday's briefing displayed data from four states that showed more than 90 percent of hospitalizations related to the virus were in unvaccinated individuals.

The press secretary also cited the rapid spread of the delta variant as a major shift in the nation's battle against the pandemic in the weeks since Biden used the Fourth of July holiday to declare independence from the virus.

"Those comments were back in May, and as I noted at the time, the delta variant was by no means the variant that it is today," Psaki said when asked about Biden's "vaxxed or masked" comments. "Ninety-nine percent of cases were not delta at the time. That was based on guidance from the CDC. Today, they’re changing their guidance. They’re changing their advice to the American public, their public health advice, based on evolving data. ... That’s exactly what they should be doing."

She also highlighted comments in Biden's speech in July in which he acknowledged the fight against the pandemic was not over, calling on Americans to get vaccinated because the virus "has not been vanquished."

Still, Biden's past comments paired with the updated CDC guidance reflect the difficulty the White House may have convincing some Americans to resume wearing masks in certain indoor settings after months of telling them they were safe to go without face coverings.

Some health experts have expressed concerns that the updated guidance from the CDC may also disincentivize getting vaccinated for some who are reluctant to get the shot if those individuals feel they will still have to wear a mask.

The CDC was criticized in May because it advised vaccinated Americans could go without a mask only two weeks after it said it was safe to do so when outdoors only, with some experts arguing the update was too swift. Now, the agency may face additional criticism for reversing course once again.

The White House has downplayed those concerns. Biden has full confidence in CDC Director Rochelle Walensky, Psaki said Tuesday, and she was adamant that the agency was doing its job to respond to an evolving situation.   

"Our goal is to save their lives," Psaki said when asked about some who may feel whiplash from the changing guidance. "And our responsibility, and the responsibility of public health officials, is to continue to provide updated guidance, if it warrants, from an evolving virus."