US President Joe Biden has unveiled his "wartime" national strategy to boost the fight against the raging COVID-19 pandemic, including making the coronavirus test followed by quarantine mandatory for all travellers coming from overseas.
Announcing the measures, 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 Biden was sworn in as the 46th president.
"In addition to wearing masks, everyone flying to the United States from another country will need to test before they get on that plane, before they depart, and quarantine when they arrive in America," Biden said at a White House event where he signed the orders.
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 in the country.
US airlines and their employees have been seeking such a federal mask mandate almost since the pandemic began, as they have struggled to deal with score of passengers who refuse to follow the airlines' own mask-wearing rules.
But the previous Trump administration had refused to enact such a mask mandate, as the ex-president himself and many in his administration often made a point of going mask-less.
Biden's plan starts with a national vaccination campaign in order to meet the President's goal of administering 100 million shots, which is enough to cover 50 million Americans with vaccines that require two doses, in his first 100 days in office.
"Our national plan launches a full-scale wartime effort to address the supply shortages by ramping up production and protective equipment, syringes, needles, you name it. And when I say wartime, people look at me like wartime? Well, as I said last night, 4,00,000 Americans have died. That's more than World War II... this is a wartime undertaking," he said.
The death toll will likely top 5,00,000 next month, he said, adding that the cases will continue to mount.
"We didn't get into this mess overnight and it's going to take months for us to turn things around but let me be equally clear we will get through this, we will defeat this pandemic, and to a nation waiting for action, let me be the clearest on this point, help is on the way," he said.
Unveiling a national strategy on COVID-19 and executive actions to beat the pandemic, Biden said this plan reflects the ideas he set forward during the campaign and they have been further refined over the last three months.
The national strategy is comprehensive and detailed, and is based on science and truth not politics and denial, he said.
He said the plan was developed with input from the nation's top infectious disease expert, Dr Anthony Fauci, among other advisers and experts. Fauci, head of the National Institute of Allergy and Infectious Diseases and Biden's chief medical adviser, was at the event at the White House, along with Biden's Covid czar Jeff Zients.
Biden said the American public would be "hearing a lot more from Dr. Fauci again, not from the President, but from the real genuine experts and scientists," in a veiled criticism of his predecessor Donald Trump.
The Trump administration was widely accused of failing to get to grips with the pandemic.
Biden said the plan starts with mounting an aggressive, safe, and effective vaccination campaign to meet the goal of administering 100 million shots in the first 100 days in office.