President Joe Biden took aim on Thursday at vaccine resistance in America, announcing policies requiring most federal employees to get Covid-19 vaccinations and pushing large employers to have their workers inoculated or tested weekly.

The new measures, which Biden laid out in remarks from the White House, would apply to about two-thirds of all US employees, those who work for businesses with more than 100 workers.

"We've been patient," Biden told the tens of millions of Americans who have declined to get coronavirus shots. "But our patience is wearing thin, and your refusal has cost all of us."

Taken together, the policies and speech represented Biden's most aggressive steps yet to prod Americans resistant to getting shots as the fast-spreading Delta variant sparks a new wave of sickness and death.

The surge has posed increased risk not just to the country but...