President Joe Biden and White House officials will resume wearing masks indoors when travelling to parts of the nation with high Covid transmission rates, as the Centers for Disease Control and Prevention prepares updated guidance that calls for fully vaccinated people to put on face coverings in high-risk places.

“We will of course be abiding by every aspect of the CDC guidelines on masking that they will provide this afternoon,” White House press secretary Jen Psaki told reporters during a press briefing Tuesday.

“That means we will be prepared to wear masks again if required,” she said.

Psaki added that the president was briefed on the updated guidance Tuesday morning by Dr. Anthony Fauci, the White House medical advisor on the coronavirus.

The Centers for Disease Control and Prevention is expected to announce the public health measure during a 3 p.m. ET briefing on Tuesday.

When asked if the White House was disappointed by the anticipated CDC guidance, Psaki noted the severity of the emerging delta variant.

“We are all dealing with an evolving virus where there’s no playbook and no historic precedent,” Psaki explained.

“What the American people should feel confident in is that we are going to continue to be guided by science and look at public health data in order to provide new guidance,” she said.

Two months ago, the CDC advised fully vaccinated people that they no longer needed to wear masks in most settings, and the White House had pitched the lead up to the July 4 holiday as a “summer of freedom” to celebrate progress made fighting the virus.

However, the highly transmissible delta variant has become the dominant strain since then, leading to a spike of infections across the country, particularly in areas with low vaccination rates. The Biden administration, after making major inroads in its vaccination campaign during the winter and spring, has struggle to boost immunization rates in recent weeks.

The weekly average of new daily Covid infections in the U.S. is more than 57,000, an increase of 65% from the week prior, according to a CNBC analysis of Johns Hopkins University data. As recently as July 5, the nation’s seven-day average of new daily infections was just below 12,000.