President-elect Joe Biden warned on Tuesday that coronavirus vaccination efforts in the United States will "slow and stall" if Congress does not urgently come up with funding.

Biden, who takes office on January 20, 2021, also pledged that his administration would carry out at least 100 million vaccinations in his first 100 days in office.

"There's a real chance that after an early round of vaccinations the effort will slow and stall," he told reporters. "We need Congress to finish the bipartisan work underway now or millions of Americans may wait months longer to get the vaccine."

Introducing members of his health team, Biden said they were "crisis-tested" and would "spare not a single effort to get this pandemic under control."

He said his priorities would be to "accelerate testing, fix our supply chain and distribute the vaccine."

Biden said he would rely on the advice of top infectious disease expert Dr Anthony Fauci, who would tell him "what I need to know, not what I want to know."

The president-elect also said he would ask Americans to wear masks for the first 100 days he is in office and require them where he is legally allowed to do so such as in federal buildings and on planes, trains and buses.

"It's not a political statement, it's a patriotic act," Biden said of mask-wearing.