Walmart on Tuesday said it is implementing an emergency leave policy for the retailer's 1.4 million hourly workers in response to the coronavirus, saying they'll receive up to two weeks pay if they have to be quarantined or are diagnosed with the illness.

The nation's largest private employer also said that if store, warehouse club or distribution center employees are not able to return to work after two weeks, up to 26 weeks of additional pay could be provided for both full- and part-time workers. The policy covers both Walmart and Sam's Club workers no matter when they were hired.

Walmart's senior vice president of U.S. benefits Adam Stavisky told the Associated Press the new policy is a response to what he called "unprecedented and uncharted times." A Walmart employee in Kentucky is among a handful of people to test positive for the coronavirus in the state. Across the U.S. there were 791 COVID-19 cases as of Tuesday, according to Johns Hopkins University.

Get Breaking News Delivered to Your Inbox

Before the coronavirus, Walmart allowed full-time hourly associate to carry over up to 80 hours of paid time off each year, and a part-time hourly associate could carry over up to 48 hours of paid time off.

Walmart's move comes a day after Darden Restaurants said it is offering paid sick leave to all hourly workers who currently lack such benefits at its food outlets. The operator of Olive Garden, Longhorn Steakhouse and other restaurants said employees would now accrue sick leave at a rate of one hour for every 30 worked, while current workers will be given credit for hours worked in their most recent 26 weeks. New employees can't use the time earned until they've worked for the company 90 days.

Darden was already planning to change its sick-leave policy, but the spread of the virus sped up its decision, a spokesperson told CBS MoneyWatch in an email.

Labor advocates say the coronavirus could take a particular toll on low-wage workers, many of whom lack paid sick time in their jobs and can't afford to stay home. That includes restaurant workers, sales clerks and other employees who work directly with customers. Meanwhile, workers who can't take time off because of the loss of earnings risks spreading the virus if they are infected.

"For those of us working in fast food, we're living paycheck to paycheck," Fran Marion, a McDonald's worker in Kansas City, Missouri, said Tuesday at a news conference organized by "Fight for $15," a union-backed labor group. A missed day of work as a result of the flu resulted in her missing a payment on her electric bill, said Marion, who earns between $70 and $90 per shift.

"There is pressure to show up no matter what. When we feel ill, calling in isn't an option," Maurilia Arellanes, a McDonald's worker from San Jose, California, said through a translator. "Sometimes managers would ask for a doctor's note, which for many of us, without access to health care, is impossible," added Arellanes, a McDonald's employee for 22 years.

Reached for comment, McDonald's said employees at corporate-owned restaurants can earn up to five days of paid time off a year. The company will also pay workers at corporate-owned outlets who must be quarantined for 14 days.

"The health and well-being of our people, our customers and our communities is our highest priority and drives our decision making," a McDonald's spokesperson said in an email. "As we proactively monitor the impact of the coronavirus, we are continuously evaluating our policies to provide flexibility and reasonable accommodations."

More than 90% of McDonald's roughly 36,000 restaurants worldwide are owned and operated by independent franchisees, and the company has not stipulated that those businesses give their workers paid time off.

McDonald's on Friday pulled the plug on a franchisee convention expected to draw 15,000 people to the Orange County Convention Center in Orlando, Florida, due to worries about the coronavirus.

CEO Chris Kempzcinski said in a video that "countries and companies alike are reassessing large gatherings." The fast-food company is taking steps to protect the health and safety of its workers, including providing more cleaning and hygiene products for its restaurants, he added.

"It's just a deplorable condition what we accept as worker benefits in this country, where missing a day of work, or a shift, could throw their entire month off in terms of bills and housing," said Judy Conti, director of government affairs at the National Employment Law Center.

The problem is particularly acute in fast food, retail and health care jobs that depend on extensive contact with the public, and makes them more likely to get sick and spread their illness. "They really are at ground zero in terms of workers and the public in terms of how this can spread," Conti said.

Although major companies like Facebook, Amazon and Microsoft have implemented work-from-home policies, only 29% of U.S. workers have that option, Bureau of Labor Statistics data show. There is no federal sick leave policy in the U.S., but 12 of the 50 states and Washington, D.C., require employers to offer paid sick leave.

"At this point, we have to join the rest of the developed world and have paid sick time for all workers," said Stuart Appelbaum, president of the Retail, Wholesale and Department Store Union in New York. "It's a selfish act for employers not to provide paid time off when society is under threat from this virus."

The answer, according to some analysts, lies in lawmakers' hands.

"Congress could pass legislation that temporarily provides paid leave to anyone who is required to go into quarantine, whether or not they actually have the virus," UBS economist Brian Rose said in a report.

— The Associated Press contributed to this report.