US President Joe Biden signed a series of executive orders to boost its fight against the deadly coronavirus pandemic.
Mr Biden signed the executive orders on Thursday, his first full day in office.
The orders include an acclerated vaccinations and testing plan, mandating masks on public transportation and directing agencies to use wartime powers to require U.S. companies to make N95 masks, swabs and other equipment.
Mr Biden said it would take months to defeat the pandemic but America would “get through this” if people stood together.
“Let me be clear – things will continue to get worse before they get better,” he said, adding that he expected the number of dead to top half a million by next month.
“This is a wartime undertaking,” he said, repeating that more Americans had already died in the pandemic than in the whole of World War Two.
Biden has taken office at a pivotal moment in the pandemic. Nearly 3,000 Americans are dying every day of Covid-19, according to data compiled by Johns Hopkins University, and newly discovered strains that are more contagious are establishing footholds.
In a break with former President Donald Trump, the policy stresses a national strategy rather than relying on states to decide what is best.
The Trump administration was widely accused of failing to get to grips with the pandemic.
In terms of total deaths from coronavirus, the US is the worst-hit country with more than 406,000 lives lost, according to Johns Hopkins University. Nearly 24.5 million have been infected.
Biden previously announced that his administration will aim to administer 100 million vaccine shots in its first 100 days.
Chief Medical Adviser Anthony Fauci spoke about the vaccine rollout, saying the Biden administration was “amplifying” the programme that was already there.
If, as hoped, 70-85% of the population was vaccinated by the end of summer, there would be “a degree of normality” by autumn, he said.
Dr Fauci said his main concern was persuading people who were sceptical about the vaccine to take it.
He added that the administration was in talks with manufacturers to produce more vaccine, amid reports of supply problems. Some regional officials say they have run out of available vaccine.
About 16.5 million shots have been administered so far.
The chief medical adviser, who served under Mr Trump, also welcomed the new administration’s emphasis on science.