(BBC) The White House is expected soon to advise Americans living in coronavirus hotspots to wear cloth masks or scarves in public to help stop the spread of the coronavirus.
President Donald Trump said “I don’t think it will be mandatory – if people want to wear them, they can”.
Residents of New York, the outbreak’s epicentre in the US, have been urged to cover their faces in public, but not to use surgical masks.
The US death toll is at least 6,000.
New York City is the worst-hit area, with 1,562 deaths in the pandemic, Johns Hopkins University reports in its daily global tally.
Both the US Centers for Disease Control (CDC) and the World Health Organization (WHO) are reassessing their guidance on face masks, as experts race to find ways to fight the highly contagious virus.
Covid-19 is carried in airborne droplets from people coughing or sneezing, but there is some dispute about how far people should distance themselves from each other.
The WHO advises that ordinary face masks are only effective if combined with careful hand-washing and social-distancing, and so far it does not recommend them generally for healthy people.
But on Thursday New York mayor Bill de Blasio urged all New Yorkers to cover their faces when outside and near others.
“It could be a scarf. It could be something you create yourself at home. It could be a bandana,” he said.
“It doesn’t need to be a professional surgical mask. In fact, we don’t want you to use the kind of masks that our first responders need.”
Dr Deborah Birx, one of President Trump’s coronavirus advisers, expressed caution about general mask-wearing. “We don’t want people to get an artificial sense of protection,” she said. “They’re an additive.”
Hospitals and morgues in New York are struggling to cope with the pandemic.
An emergency field hospital now stands in Central Park, and another makeshift hospital is to be set up in the city’s Javits Center, a conference venue.
Most states in the US have issued “stay-at-home” orders, putting more than 75% of Americans under lockdown.
More than a million cases of coronavirus have been registered globally, according to Johns Hopkins University.
Nearly 53,000 people have died and more than 210,000 have recovered.