Twenty American states require people to wear masks and face coverings when out in public, but there is no national mask mandate, and some Democrats and Republicans are calling for one to be put in place.
"Actually, I had a mask on".
Democratic presidential candidate Joe Bidensaid on Wednesday that his party has assembled a group of 600 lawyers and thousands of other people to prepare for possible "chicanery" ahead of November's election.
However, the President remained defiant - despite increasing evidence that face masks could not only prevent the transmission of infection but can also help in unburdening the health infrastructure. "I had a mask on for a period of time", he said.
In early April, the Centres for Disease Control and Prevention (CDC) recommended that people wear cloth face coverings in public settingswhere other social distancing measures were hard to maintain.
White House press secretary Kayleigh McEnany defended Trump Tuesday by saying the information, which first appeared in The New York Times, had not been verified by the intelligence committee.
Mr Trump immediatelyundercut the CDC guidance by flatly stating that he would not follow it.
Trump immediately undercut the CDC guidance by flatly stating that he would not be following it, suggesting it would be unseemly for the commander-in-chief to wear a mask as he meets with heads of state. By the start of February, the Centre for Disease Control (CDC) issued its first formal guidance on its website, saying that the agency "does not now recommend the use of face masks among the general public".
'It was a dark, black mask and I thought I looked OK. "I can name 'kung flu.' I can name 19 different versions of them".
In June, during a sit-down with the Wall Street Journal, Trump politicized the issue further by suggesting that some people wore mask to 'signal disapproval of him, ' the newspaper said.
California Governor Gavin Newsom on Wednesday closed bars, banned indoor dining and imposed other restrictions in 19 counties, including Los Angeles, affecting over 70% of the most populous US state.
On Wednesday, the same day Conway talked to reporters, Trump said he was open to wearing a mask in close confines, but didn't think a nationwide mask mandate was necessary.
Biden's announcement comes as top disease researcher Anthony Fauci told the US Senate that he "would not be surprised" if new virus cases in the country reach 100,000 per day, the BBC reported.