President Biden is announcing sweeping new vaccine mandates Thursday that will affect tens of millions of Americans, ordering all businesses with more than 100 employees to require their workers to be inoculated or face weekly testing.

Biden also will require all health facilities that accept Medicare or Medicaid funding to vaccinate their workforces, which the White House believes will impact 50,000 locations.

And the president plans to sign an executive order that would require all federal employees to get vaccinated against the coronavirus — without an option for those who prefer to be regularly tested instead — in an effort to create a model he hopes state governments and private companies will adopt.

The cluster of new policies comes as the country grapples with the highly contagious delta variant, which has sent cases surging to more than 150,000 a day and is causing more than 1,500 daily deaths. The White House has struggled to convince hesitant Americans to get vaccinated and has been increasingly shifting toward requirements.

The changes also come as Biden’s approval rating has fallen in recent weeks, with Americans less supportive of his handling of the pandemic. Defeating the pandemic was among his central promises, and White House aides believe that his ability to deliver on it will be critical to the success of his presidency.

The White House released an 11-page memo Thursday entitled “Path Out of the Pandemic” that outlined six key areas where Biden is either shifting or hardening his strategy on the virus.

The most far-reaching is a new regulation to be written by the Labor Department that will require all businesses with more than 100 employees either to mandate vaccinations for all their workers, or require them to take weekly coronavirus tests. The White House estimates that the policy will impact about 80 million workers, or two-thirds of the country’s workforce.

Businesses that ignore the policy, once it’s in place, could trigger penalties of up to $14,000 per violation, according to a senior Biden administration official, who briefed reporters on the plan ahead of the president’s speech under the condition that his name would not be used.

Businesses also will be required to give workers paid time off to get vaccinated, according to the new rules.

“This plan will ensure that we are using every available tool to combat COVID-19 and save even more lives in the months ahead, while also keeping schools open and safe, and protecting our economy from lockdowns and damage,” according to a copy of the memo.

In early August, The Washington Post reported that the White House was considering these moves. The White House, at the time, only confirmed that mandates were imminent for nursing homes and other long-term health-care settings.

With respect to the new mandate for federal workers, the new vaccine requirement will apply not just to the roughly 2.1 million federal employees but also to the millions of contractors that do business with the government. It follows a policy announced by the Pentagon in August making vaccinations mandatory for the military.

Unlike a requirement for federal workers Biden announced earlier this summer, the executive order will no longer allow regular testing to serve as a substitute for vaccination, according to a person familiar with the plans who was not authorized to comment publicly and spoke on the condition of anonymity.

White House press secretary Jen Psaki, speaking ahead of Biden’s remarks on Thursday, said federal workers will have roughly 75 days to be fully vaccinated. If employees do not comply, they will undergo the standard disciplinary process for federal workers, she said.

There will be exemptions from the mandate for people with disabilities, or those who decline for religious reasons.

“We would like to be a model to what we think other businesses and organizations should do around the country,” Psaki said.

Beyond making millions of Americans subject to the new rules, the president has made clear he wants to set an example, creating the political and social space for state and local government officials to follow suit and for large corporations to do the same.

Some local authorities have already begun taking similar steps. The Los Angeles County school district is considering a proposal that would mandate vaccinations for those 12 and up to be able to attend school in person as anxieties mount about school reopenings.

Several large businesses, including Walmart, McDonald’s and Delta Air Lines, followed with vaccine mandates of their own shortly after Biden announced the policy in late July that would require federal workers to get a vaccination or be subject to testing twice a week. At the time, the White House cast the policy as a bold step that would allow federal agencies to safely resume operations in the office and in person. Those found to be lying about their status were to face discipline or possible dismissal.

But in the month and a half since that order, the delta variant has presented a major challenge to efforts to get the pandemic under control. The political landscape has also appeared to shift — vaccinations started ticking back up after stagnating for several weeks, with many hesitant Americans driven by fear of the delta variant’s lethality or compelled to get shots because of workplace mandates. The Food and Drug Administration also granted the Pfizer-BioNTech vaccine full approval, making it easier for the government and businesses to impose mandates. The agency is expected to grant full approval to vaccines from Moderna and Johnson & Johnson in the coming months.

Until now, Biden has stopped short of using the power of the federal government to force states and businesses to put mandates in place, instead opting to lead by example. Still, opposition to mandates has hardened among Republican governors such as Florida’s Ron DeSantis and Texas’ Greg Abbott.

Significant questions remain about the implementation of Biden’s new order. The earlier policy, which allowed testing as an alternative to vaccinations, is only now being rolled out, after it took weeks for the administration to come up with guidance for managers.

Issues arose, including how supervisors could keep rosters of their employees’ status and how they should address those who refused to provide information on their vaccination or testing status.

It is unclear what percentage of federal employees have not been vaccinated, and the White House declined to provide figures on Thursday. Psaki said individual federal agencies keep track of vaccination statistics for their respective workforces.

Unions that represent federal employees demanded that management bargain over the conditions of the policy. And many federal employees in states with low vaccination rates said they would continue to refuse the shots, potentially risking discipline or firing.

Thursday’s executive order raises similar issues that could delay the rollout. While it is clear the administration can make vaccinations a condition of employment, unions will probably want to bargain over how long employees will have before they must get immunized, what evidence they will need to prove their status, and what kind of administrative leave they will receive to get vaccinated.

Enacting such procedures for the nation’s largest employer will be complicated.

In the meantime, hopes have dimmed that federal agencies will be able to bring their staffs back to the office this fall, raising new concerns about government services that require face-to-face interaction with the public, from Social Security benefits to tax questions.

The Department of Housing and Urban Development, for example, told its employees this week that the agency would remain in “maximum telework status” through the end of the year.

BY ANNIE LINSKEY, YASMEEN ABUTALEB, SEUNG MIN KIM AND LISA REIN, THE WASHINGTON POST