Top White House Covid officials called for private employers to mandate vaccines at a briefing Tuesday, one day after the Food and Drug Administration granted full approval to Pfizer for its coronavirus vaccine.

Many companies have responded to this summer’s surge in Covid cases by rolling out vaccine requirements for all or part of their U.S. staff, including Google, Facebook and United Airlines. But others have avoided vaccine mandates, both to give the FDA time to approve a full license and to keep vaccine hesitant workers from leaving.

“If you’re a business, a nonprofit, a state or local leader who has been waiting for full and final FDA approval before you put vaccination requirements in place, now is the time,” White House Coronavirus Response Coordinator Jeffrey Zients said at the briefing. “You have the power to protect your communities and help end the pandemic through vaccination requirements.”

The Equal Employment Opportunity Commission allows vaccine mandates for any personnel returning to the office as long as companies provide exemptions in accordance with the Americans with Disabilities Act and the Civil Rights Act of 1964. Mandates have sparked controversy over the last year, with several states restricting mask and vaccine requirements in government, education and private business.

The briefing comes after President Joe Biden asked companies and local officials on Monday to start imposing vaccine mandates in light of the FDA’s full approval. Biden previously announced that federal workers would have to submit weekly Covid tests and wear masks if they opt not to get vaccinated, with his administration issuing similar directives for the Departments of Health and Human Services and Veterans Affairs.

“Do what I did last month: require your employees to get vaccinated or face strict requirements,” Biden said Monday.

Vaccination could help us get Covid-19 under control by the spring of 2022, according to the medical advisor to the president, Dr. Anthony Fauci.

“I would like to appeal to the people in the country who are not vaccinated to realize that we have the capability among ourselves to essentially cut down the timeframe to getting to the end of this pandemic,” Fauci said during the briefing Tuesday.  “Get vaccinated and the timeframe will be truncated dramatically.”

The U.S. reported a seven-day average of more than 150,000 new coronavirus cases as of Monday, an increase of 12% from a week ago, according to a CNBC analysis of data from Johns Hopkins University. Motivated by the highly transmissible delta variant, some local governments have already begun enforcing vaccine mandates on select businesses.

In San Francisco, customers of the city’s indoor restaurants, gyms, and entertainment centers must now provide proof of full vaccination upon entry, while employees must do the same by Oct. 13. New York City’s vaccine mandate applies to all the same venues, though their patrons and staff are only required to receive one vaccine dose by Sept. 13.