NEW YORK (CNN/WCCO) — Walmart, the world’s largest retailer, is the latest national chain to require all customers to wear masks.

The change will start next week on July 20.

READ MORE: No Injuries After Train Derailment In Plymouth

Meanwhile, Starbucks said last week that it will require customers to wear facial coverings or masks in all 9,000 of its company-owned US stores beginning Wednesday. Best Buy announced Tuesday that it will also require all shoppers coming into its approximately 1,000 stores to wear face masks. Costco began requiring its members to wear masks in stores beginning in May.

Although no federal mandate to wear a mask exists, the Centers for Disease Control and Prevention says everyone “should wear a cloth face cover when they have to go out in public.” The CDC said “face coverings are meant to protect other people.”

Most major retailers and grocers initially hesitated to enact their own mask mandates for customers during the pandemic, partly over fears of antagonizing shoppers who refuse to wear them. Retailers have said they are reluctant to put their employees in the position of enforcing mask requirements.

But the ground in the retail and restaurant industries has shifted in recent weeks as the coronavirus pandemic worsens. More than 3.3 million people have now tested positive for the coronavirus nationwide and more than 130,000 have died. Cases are climbing in much of the country and many cities and states are reimposing restrictions to contain new outbreaks, including mask requirements in public settings.

“As the number of confirmed cases has spiked in communities across the country recently, so too have the number and types of face covering mandates being implemented,” Walmart said in a news release Wednesday.

READ MORE: George Floyd's Cause Of Death, Derek Chauvin's Force Will Be Keys At Trial

About 65% of its more than 5,000 stores, including its Sam’s Club locations, are located in areas where there is government mandate on face coverings.

“While we’re certainly not the first business to require face coverings, we know this is a simple step everyone can take for their safety and the safety of others in our facilities,” Walmart said.

Walmart says the July 20 date will give the company time to inform customers and members of the changes. It will also allow time for the company to post signage and train associates on the new protocols.

Industry groups and unions have also stepped up their calls around mask requirements for customers.

Last week, the Retail Leaders Industry Association, an industry trade group, called on the nation’s governors to pass statewide mandates requiring citizens to wear masks in public. The United Food and Commercial Workers’ Union also urged government officials and business leaders to require masks for customers in an advertisement over the weekend.

MORE NEWS: Minnesota Man Struck And Killed While Changing Tire On South Dakota Highway

(© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. CNN contributed to this report.)