In an effort to slow the spread of the coronavirus, the Trump administration is formalizing a new health guidance to recommend that many people living in coronavirus hotspots states wear facemasks when leaving home
The health guideline recommend which is still being finalised on Thursday would apply at least to those who live in areas hard-hit by community transmission of the Covid-19 virus
A person familiar with the White House coronavirus task force's discussion said officials would suggest that nonmedical masks, T-shirts or bandannas be used to cover the nose and mouth when going out for essential trips.
Medical-grade masks, particularly short-in-supply N95 masks, would be reserved for those dealing directly with the sick.
US Surgeon General Dr Jerome Adams and other officials have stressed that surgical face masks and other protective medical equipment have been in short supply and must be prioritised for people such as healthcare workers.
A Centres for Disease Control and Prevention (CDC) draft of the guidance would make the covering recommendation apply to nearly all Americans, all over the country, according to a federal official who has seen the draft but was not authorised to discuss it.
Some exceptions would be young children under age two, anyone who has trouble breathing or anyone who is unable to remove the covering without help.
Officials were still discussing whether to limit the recommendation's geographic scope.
Under the previous guidance, only the sick or those at high risk of complications from the respiratory illness were advised to wear masks.
The new proposal was driven by research showing that some infections are being spread by people who seem to be healthy.
In response to recent studies, the CDC on Wednesday changed how it was defining the risk of infection for Americans. It essentially says anyone may be considered a carrier, whether they have symptoms or not.
US officials have been telling people to stay at home as much as possible, and keep at least six feet (two metres) away from others when they do go out. Other advice includes frequent handwashing and not touching your face.
But until now, federal officials have stopped short of telling people to cover their faces out in public.
'No exact evidence'
The World Health Organization on Monday reiterated its advice that people in the general population do not need to wear face masks unless they are sick. Since the epidemic began in China, the WHO has said masks are for the sick and for people caring for them.
Separately, a 2013 study tested whether homemade masks might help during a flu pandemic. It found surgical masks were three times more effective in catching droplets from coughing people than masks made from cotton T-shirts, though it's not clear if the new coronavirus behaves exactly like flu viruses.