A senior aide to President Donald Trump has conceded that the US is “not going to control the pandemic”.
Instead White House Chief of Staff Mark Meadows said Covid-19 could only be defeated by “mitigation areas” like vaccines and therapeutics.
His remarks come as coronavirus cases surge in the US, nine days before the country’s presidential election.
US Vice-President Mike Pence has continued to campaign despite positive tests on his team.
Mr Pence and his wife both tested negative on Sunday, his office said.
Some 225,000 Americans have died since the pandemic began, the highest figure of any country.
Addressing supporters in New Hampshire on Sunday, President Trump repeated his claim that the US was turning a corner with the pandemic, despite recording record numbers of infections and rising hospital admissions.
No vaccine has yet completed clinical trials.
Mr Trump – who campaigned in North Carolina, Ohio and Wisconsin on Saturday – is scheduled to appear at two rallies in Pennsylvania today, before making his way to Michigan, Wisconsin and Nebraska on Tuesday.