One year after the US was brought to a near-standstill by the coronavirus, President Joe Biden has used his first prime-time address to announce his plan to make all adults vaccine-eligible by May 1 and “begin to mark our independence from this virus”.

In his first national address since taking over as president, Mr Biden offered Americans fresh hope and appealed anew for their help.

Speaking from the White House East Room on Thursday night (US time), Mr Biden offered Americans fresh hope and appealed anew for their help.

He announced moves to speed up vaccinations, including lifting eligibility qualifications, deploying an additional 4000 active-duty troops to support vaccination efforts and allowing more people – such as medical students, veterinarians and dentists – to deliver shots.

He is also directing more doses toward 950 community health centres and up to 20,000 pharmacies to make it easier for people to get vaccinated closer to their homes.

His aim: Let Americans gather at least in small groups for the July 4 holiday and “make this Independence Day truly special”.

“I need you to get vaccinated when it’s your turn and when you can find an opportunity, and to help your family, your friends, your neighbours get vaccinated as well,” he said.

“If we do this together, by July 4 there’s a good chance you, your families and friends will be able to get together in your backyard or in your neighbourhood and have a cook-out on a barbecue and celebrate Independence Day.

“That doesn’t mean large events with lots of people but it does mean small groups will be able to get together. After this long, hard year, that will make this independence Day something truly special.”

Mr Biden was marking one year since the onset of the pandemic that has killed more than 530,000 Americans and disrupted the lives of countless more.

“While it was different for everyone, we all lost something,” he said, calling the past year “a collective suffering, a collective sacrifice”.

Mr Biden had pledged to have 100 million shots of coronavirus vaccine in his first 100 days in office. On Thursday, 50 days into his presidency, he said that the national vaccination campaign was on target to beat that target easily.

“We’re actually on track to reach this goal of 100 million shots in arms on my 60th day in office. No other country in the world has done this – none,” he said.

Earlier, Mr Biden signed into law a $US1.9 trillion ($A2.5 trillion) relief package that he said would help defeat the virus, nurse the economy back to health and deliver direct aid to Americans in need. Some direct cheques could begin arriving this weekend.

“This historic legislation is about rebuilding the backbone of this country,” Mr Biden said as he signed the bill in the Oval Office.

Most noticeable to many Americans are provisions providing up to $US1400 ($A1800) in direct payments and extending $US300 weekly emergency unemployment benefits into early September.

Also included are expanded tax credits for the next year for children, child care and family leave, plus spending for renters, feeding programs and people’s utility bills.

In his Thursday night address, Mr Biden said that as vaccine supplies continued to increase, he would direct states and territories to make all adults in the US eligible for vaccination by May 1. The US is expecting delivery of enough doses for those 255 million adults by the end of that month, but the process of actually administering those doses would take time.

Even as he offered optimism, Mr Biden made it clear that the July 4 timetable also required co-operation from Americans to continue to wear face coverings, maintain social distancing and follow federal guidelines.

He also called on them roll up their sleeves to get vaccinated as soon as they were eligible.

“I need you, the American people,” he said. “I need you. I need every American to do their part.”

The House gave final congressional approval to the sweeping package by a near party line 220-211 vote on Wednesday, seven weeks after Mr Biden entered the White House and four days after the Senate passed the bill.

Republicans in both chambers opposed the legislation unanimously, characterising it as bloated, crammed with liberal policies and heedless of signs the crises are easing.

Almost exactly one year ago, then-president Donald Trump addressed the nation to mark the WHO’s declaration of a global pandemic. He announced travel restrictions and called for good hygiene but displayed little alarm about the forthcoming catastrophe.

Mr Trump later acknowledged he had been deliberately “playing down” the threat of the virus.

-with AAP