President Joe Biden has signed a raft of executive orders to boost the fight against Covid which has ravaged the US.
Vaccination will be accelerated and testing increased. Emergency legislation will be used to increase production of essentials like masks.
Announcing the 10 measures, Mr Biden said it would take months to defeat the pandemic but America would "get through this" if people stood together.
The moves come a day after Mr Biden was sworn in as the 46th president.
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.
Mr Biden said that the "bold practical steps" that he was taking would not come cheaply.
"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.
He mentioned the vaccine, saying that its rollout had been a "dismal failure so far", and described his plan for 100 million jabs in his first 100 days in office as "one of the greatest operational challenges our nation has ever taken on".
But when challenged by a reporter who suggested the target might be too low, he snapped back: "When I announced it you all said that it's not possible. Come on. Give me a break, man."
Mr Biden also promised to be transparent about setbacks, and allow scientists to work free from political interference.
"I'm convinced the American people are ready to spare no effort to get this done," he concluded. "We can do this if we stand together."