Texas Governor Greg Abbott has issued an executive order that all Texans don face coverings in public in counties with 20 or more Covid-19 cases.
Texas has seen a surge of hospital admissions in recent days, hitting a record high of more than 8,000 virus cases in a single day on Wednesday.
“Wearing a face covering will help us to keep Texas open for business,” Mr Abbott said, announcing the order.
After an initial warning, those who refuse will face a fine up to $250.
Texas was at the forefront of states loosening lockdown measures that were meant to curb the spread of the coronavirus. Mr Abbott allowed his initial stay home order to lapse on 30 April, with almost all businesses operating to at least 50% capacity by early June.
But as the virus surged, Mr Abbott began to walk back his state’s reopening last week, ordering all bars shut and cutting restaurant capacity from 75-50%.
“Covid-19 is not going away,” Mr Abbott, a Republican, said on Thursday. “In fact it’s getting worse.”
He added: “We are now at a point where the virus is spreading so fast there is little margin for error.
“If we want to avoid lockdowns, if we want to protect those we care about, we need all Texans to join this effort.”
The order includes a series of “common sense” exemptions, including children who are 10 years old or younger, those who have a medical condition that prevents them from wearing a mask, people who are eating or drinking and those who are exercising outdoors.
Mr Abbott had initially resisted a state-wide order on masks, going so far as to ban local governments from requiring facial coverings.
“Let me be clear: no-one can ever be put in jail for violating this safe practice,” the governor said of the order.
He added: “Today Covid is spreading like never before and the virus, it doesn’t know and it doesn’t even care what your age, race, sex, political affiliation or geographical affiliation is.
“It will attack anyone anywhere.”
What Texans think
Rachel Moon, 23, a sales rep in Houston
When we reopened, my friends all went to the Houston bars, and they have all tested positive now.
I’m a Republican, but I don’t think Trump should be enforcing rules if he isn’t following them. I don’t agree with how he acts. I think that if he led by example, more likely people would follow and wear masks.
But I think Governor Abbott and his team have done everything they can do.
Genesis Valbuena, 26, project manager, Austin
Some bar owners here in Austin are vocally going against what we need to do – criticising the data and suing the government for shutting them down.
If we continue to do this, we are going to be shut down for the rest of the year. For me that’s completely narcissistic. How certain bar owners are acting is ludicrous. The reopening should have been done less quickly.
I think initially the decision by local and state government, who closed down everything quickly, was made out of fear instead of data.
The use of masks has become a political flashpoint in the US.
Last week, Texas’ state capital of Austin saw a demonstration led by radio show host and prominent conspiracy theorist Alex Jones protesting against the city’s mask requirements.
President Donald Trump said yesterday he was “all for masks”, a shift in tone to his reluctance to wear a face covering in public, though he maintained mandatory mask rules were unnecessary.
But the move by Mr Abbott was described as “far too little, far too late” by Texas Democratic Party Communications Director Ahbhi Rahman.
“Texans are still getting sick. Families are still suffering… All of this could have been prevented if Governor Abbott had listened to experts and medical professionals in the first place.”
The World Health Organization (WHO) said last month that masks should be worn in public where social distancing is not possible to help stop the spread of coronavirus.
The global body, which previously argued there was not enough evidence to say that healthy people should wear masks, said later that new information showed they could provide “a barrier for potentially infectious droplets”.