US President Joe Biden has announced sweeping new Covid-19 measures that require workers at large companies to be vaccinated or face weekly testing.
The measures also include a vaccine mandate for millions of federal government workers and come as cases in the country are surging.
Hospitals in several states have been reached capacity amid the spread of the more transmissible Delta variant.
Mr Biden’s order will affect about 80 million workers.
“This is not about freedom, or personal choice, it’s about protecting yourself and those around you,” the president said as he unveiled his plan.
More than 650,000 Americans have died with Covid-19 since last year.
Mr Biden announced his plan in a speech at the White House on Thursday.
He said he had directed the US Department of Labor to require all private businesses with 100 or more staff to mandate the jab or request proof of a negative coronavirus test from employees at least once a week.
Nearly 17 million other healthcare workers at facilities receiving federal benefits will also face the same requirements, he said.