US president-elect Joe Biden has said "more people may die" if outgoing President Donald Trump continues to block efforts to plan for a US transition of power as the Covid-19 pandemic worsens.
Mr Biden also said business and labour leaders had signalled willingness to cooperate to fix the pandemic-battered US economy but stressed the virus first must be brought under control, and urged Congress to pass relief legislation.
The Democratic president-elect delivered a speech and took questions from journalists in Wilmington, Delaware, after consulting with the CEOs of top US companies and labour leaders.
He welcomed further progress in Covid-19 vaccine development, and added that he would not hesitate to get vaccinated.
Mr Biden said the CEOs and labour leaders were "ready to come together" and that "the unity was astounding."
Mr Biden will inherit an economy that has suffered millions of job losses during a pandemic that has killed more than 246,000 people in the United States. US Covid-19 cases are also surging as Mr Biden prepares to take office on 20 January.
"We're going into a very dark winter. Things are going to get much tougher before they get easier," Mr Biden said of the pandemic.
In response to a question about the consequences of the Trump administration not cooperating with the Biden transition team on fighting the pandemic, he said, "More people may die if we don't coordinate."
"As you battle Covid, we have to make sure that businesses and workers have the tools, the resources and the national guidance and health and safety standards to operate safely," Mr Biden added.
Mr Biden said it would be a lot easier for the presidential transition if Mr Trump were to cooperate but said of the incumbent's refusal to concede: "I find this more embarrassing for the country than debilitating for my ability to get started."
US President-elect Joe Biden has expressed frustration about Donald Trump's refusal so far to cooperate on the White House transition process. He says that 'more people may die' without immediate coordination on fighting the Covid-19 pandemic. pic.twitter.com/SmXWlU7sNa
— RTÉ News (@rtenews) November 16, 2020
He called for bipartisan cooperation against the pandemic and urged Congress to pass pandemic relief legislation. Talks on such legislation stalled for months before the 3 November election.
Mr Biden said the coronavirus continues to spread "almost unabated" and that it was state governors who were stepping up.
On other economic matters, Mr Biden said he plans to pursue "a fairer tax structure", and that no government contracts will be given to companies that do not make products in the United States.
Mr Biden earlier said Moderna's announcement that its experimental Covid-19 vaccine was 94.5% effective based on interim data from a late-stage trial provided fresh hope for beating the coronavirus.
Coupled with positive results last week on a rival Pfizer shot, Moderna's news added to optimism that widespread vaccination in the coming months could help tame the pandemic.
Asked whether he personally would be willing to get vaccinated with one of the newly developed shots, Mr Biden said, "I wouldn't hesitate to get the vaccine."
"They appear to be ready for prime time, ready to be used," he said of the two vaccine candidates.
Mr Biden also urged Americans to limit the number of people at gatherings for next week's Thanksgiving holiday, with social distancing and masks encouraged.
Unlike in 2008, when the country elected Democrat Barack Obama and his running mate Biden as the global economy teetered from the sub-prime mortgage crisis, the worst of the current conomic downturn may have passed. Unemployment has come down sharply from its April peak of 14.7% to 6.9% and is projected to fall further throughout next year.
Mr Biden moved ahead with economic planning even as Mr Trump today again refused to accept his election loss.
Mr Trump's national security adviser, Robert O'Brien, said he was prepared to ensure a professional transition to Mr Biden's team.
"If the Biden-Harris ticket is determined to be the winner, and obviously things look like that now, we'll have a very professional transition from the National Security Council, there's no question about it," Mr O'Brien said.
Mr Biden beat Mr Trump by the same 306-232 margin in the state-by-state Electoral College that prompted Mr Trump to proclaim a "landslide" victory in 2016.
Mr Biden also won the national popular vote by at least 5.5 million votes, with some ballots still being counted.
Mr Trump has made no headway with legal challenges in multiple states so far.
"I won the Election!" he wrote on Twitter earlier, again falsely claiming victory.
I WON THE ELECTION!
— Donald J. Trump (@realDonaldTrump) November 16, 2020
Twitter posted a disclaimer saying, "Official sources called this election differently."
Election officials from both parties have said there is no evidence of major irregularities.
Federal election security officials have decried "unfounded claims" and expressed "utmost confidence" in the election's integrity.