President Donald Trump has announced his administration is encouraging Americans to wear face masks in public - but said he will not be doing so.
Mr Trump stressed the recommendation that people cover their faces in public is optional.
The new guidelines, set to be announced, will encourage people to use more rudimentary covering like t-shirts, bandannas and non-medical masks.
The expected recommendation has prompted concerns that the market could be tested in its ability to accommodate a sudden surge in demand.
The introduction of face covering guidance is expected to be limited to people in areas of the USA hit most hard by the coronavirus, not nationwide, despite the suggestions of health officials.
In an address at the White House - foreshadowing the official announcement - the president tried to limit any panic buying by stressing the measures were recommendations and not requirements.
Mr Trump even suggested scarves could be an good alternative to masks.
"If people wanted to use scarves - which they have, many people have them - they can. In many cases, the scarf is better, it's thicker," the president said.
He added that the guidance was not mandatory "because some people don't want to do that" and "people can pretty much decide for themselves right now."
Under previous guidance, only the sick - or those in high risk groups - were advised to wear masks.
Initial draft guidance from US health authority the Centers for Disease Control and Prevention (CDC) envisioned the new recommendations would apply to all Americans - not just those in hot-spot areas.
But federal officials limited the recommendations to places with high rates of Covid-19 community spread.
The updated recommendations comes as states in the US are bracing for critical shortfalls in equipment like those that other parts of the world have experienced.
In New York, Governor Andrew Cuomo announced he would use his authority to seize ventilators and protective gear from private hospitals and companies were they are not being used.
Coronavirus: Everything you need to know