The US will also deploy more military medics amid fears the holiday season will spark a Covid spike.
US President Joe Biden has said 500 million Covid rapid tests will be made available at no cost amid new measures to tackle the surging Omicron variant.
In a Tuesday address, Mr Biden also announced expanded testing and military support for hospitals, but said lockdowns were not yet on the horizon.
“This is not March of 2020,” he said. “We’re prepared. We know more.”
Omicron has become the dominant strain in the US, accounting for nearly three-quarters of all new cases.
It was first identified in southern Africa last month but has now spread around the globe.
Only one death in the US has been linked to the new variant: a 50-year-old from Harris County, Texas, who had an underlying health condition and was unvaccinated.
Although 73% of adult Americans are fully vaccinated against Covid, the administration remains concerned about those who have not had jabs.
Speaking on Tuesday, Mr Biden again implored Americans to protect themselves and get vaccinated.
He acknowledged that some vaccinated Americans would also be infected but he stressed that the unvaccinated have “a significantly higher risk of ending up in the hospital, or even dying”.
“If you’re not fully vaccinated you have reason to be concerned,” said an unmasked Mr Biden, who coughed into his hand during his remarks.
Those who have been vaccinated and have had no exposure to Covid-19 may go ahead with Christmas celebrations, the president said.
The White House said the new measures would “mitigate the impact unvaccinated individuals have on our healthcare system”.
In the same speech, he acknowledged that his vaccine mandates have been “unpopular”.
“My administration has put them in place not to control your life, but to save your life and the lives of others,” he said.
It comes after a White House rule that would require US businesses with more than 100 employees to require Covid vaccination was permitted to go forward by a federal judge. The issue may eventually wind up at the Supreme Court.
Mr Biden also offered rare praise for former President Donald Trump, who was booed on Sunday after telling an audience in Dallas, Texas, that he had received his booster shot.
“Maybe one of the few things he and I agree on,” Mr Biden said of his political rival.
- 500 million at-home rapid tests (antigen/flow) will be bought and delivered free to all Americans who request them from January. Kits can currently cost $7-$15 (£5-£11) over-the-counter and availability can be sketchy in some areas
- 1,000 military medical personnel will be deployed to hospitals nationwide over the next two months, five times the current amount
- The launch of new federal testing sites nationwide, with the first in New York City – which has seen a massive surge in Omicron – by Christmas
- Expanded hospital capacity and distribution of critical supplies
Omicron has created concern in a number of US cities, with people in New York, Washington and elsewhere queuing up for tests ahead of meeting up with family members.
Criticism of the US testing system has mounted in recent weeks, as at-home test kits are expensive and hard to find. The US lags behind other countries in terms of testing.
In the UK, at-home tests are provided for free from the government, and are otherwise much cheaper to purchase.
In Tuesday’s speech, Mr Biden denied that the roll out of widespread testing had lagged. “It didn’t take long at all,” he said.
Covid-19 cases in the US nationally are up 57% since the start of this month, Reuters reports.
As the purchase of 500 million tests was announced, White House press secretary Jen Psaki expressed regret for having poured scorn on the idea just two weeks ago.
When a reporter asked on 6 December why the Biden administration had not made at-home tests available free to every citizen, as the UK and Singapore have done, Ms Psaki shot back: “Should we just send one to every American? Then what happens if every American has one test? How much does that cost, and then what happens after that?”