Editor's note: This story has been updated to include President Donald Trump's signing of the executive order.

President Donald Trump on Tuesday ordered beef, pork and poultry processing plants to remain open despite safety concerns.

Citing his authority under the Defense Production Act, Trump declared in an executive order that "it is important that processors of beef, pork, and poultry ('meat and poultry') in the food supply chain continue operating and fulfilling orders to ensure a continued supply of protein for Americans."

Critics said the forced openings — some plants have closed because so many employees contracted the coronavirus – threaten the safety of workers who remain vulnerable to the disease.

Trump also told reporters he would seek to shield meat plants from legal liability if they are sued by employees who contract coronavirus while on the job, USA TODAY reported. While Trump only mentioned Tyson Foods specifically, he suggested his plan would protect other businesses from liability as well.

Some Iowa Democrats questioned how companies can keep workers safe.

The United Food and Commercial Workers International Union said Tuesday that 20 frontline workers have died from the novel coronavirus that they contracted while working in meatpacking plants, including at least three workers in Iowa. Another 6,500 U.S. employees have become either ill or were exposed to the virus.

► More:The latest on coronavirus in Iowa

U.S. Rep. Cindy Axne said any order from Trump or a company to stay open needs to come with "ironclad answers" on how employees will be protected.

"For these plants to reopen," U.S. Rep. Dave Loebsack tweeted, "extraordinary efforts are needed to guarantee they are clean and that the workers are healthy and able to remain safe while keeping the plants running and feeding America."

Nationally, 22 pork, chicken or beef plants have closed at some point since the public health emergency began. About 25% of pork and 10% of beef processing is offline, experts estimate.

Pork producers in Iowa have lost as much as 40% of their hog production capacity, officials estimate. That means as many as 40,000 hogs in Iowa are not getting processed each day.

► More:'Horrible choices': Iowa livestock producers may have to euthanize pigs as packing plants struggle

Iowa pork producers have warned that they will have to destroy pigs that they're unable to move to meatpacking plants. Large processing plants in Iowa, Minnesota and South Dakota have closed.

Gov. Kim Reynolds and U.S. Sens. Chuck Grassley and Joni Ernst welcomed the news on social media.

The Iowa Republicans, along with Iowa Agriculture Secretary Mike Naig, asked the Trump administration Monday to invoke the Defense Production Act to help reopen pork plants and provide financial assistance for producers that need to depopulate herds.

Concerns about possible meat supplies peaked this weekend when Tyson Foods, which closed a pork processing plant in Waterloo last week, ran a full-page ad in the New York Times Sunday.

It warned that the country faces a meat shortage: "As pork, beef and chicken plants are being forced to close, even for short periods of time, millions of pounds of meat will disappear from the supply chain.

"As a result, there will be limited supply of our products available in grocery stores until we are able to reopen our facilities that are currently closed," wrote John Tyson, chairman of the Arkansas company's board.

Community leaders and unions continued Tuesday to express concerns about worker safety.

"There are now 1,000 positive cases of the virus in my community, and the path of destruction leaves behind orphans, families and friends," said Chris Schwartz, a Black Hawk County supervisor, who pushed Tyson to close its pork processing plant with growing COVID-19 cases.

The president "doesn't have a clue about what's happening in communities like mine," Schwartz said, adding that it would be "totally reckless for the president to prematurely mandate" that Tyson or any other company reopen plants before adequate safety measures were in place.

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Joe Henry, a Des Moines Latino leader, said the president is putting corporations before workers, who lack adequate access to health care.

Workers who have become severely ill with COVID-19 sometimes face medical bills that reach $40,000, said Henry, president of the League of United Latin American Citizens Council No. 307 in Des Moines. Trump should require testing of all meatpacking workers, and the companies should be made to pay all employee sick leave and health care costs linked with coronavirus outbreaks at the plants, he said.

"The president has got it wrong," Henry said.

U.S. Rep. Abby Finkenauer, an Iowa Democrat, said the Trump order must be accompanied with "stringent, enforceable worker-safety protections, widespread rapid testing and adequate personal protective equipment."

“We owe it to the essential employees who are literally putting their lives on the line to keep food on our tables,” Finkenauer said in a statement.

The National Pork Producers Council said Tuesday that it was waiting for more details. But it added that by triggering the act, "the federal government will prioritize the continuity of pork processing plant operations and hopefully provide support for euthanizing and disposing of pigs in an orderly and humane way."

The U.S. Department of Agriculture said late Friday that livestock and poultry producers face an "unprecedented emergency" after large processing plants have slowed or closed.

The USDA said it would work with state officials and veterinarians to help farmers "identify potential alternative markets … and if necessary, advise and assist on depopulation and disposal methods."

The United Food and Commercial Workers said Tuesday that meatpacking employees must be given the same priority as first responders, with increased worker testing, priority access to personal protective equipment, an end to waivers that allow companies to increase line speeds, and mandated social distancing.

Information from the USA TODAY network contributed to this report.

Donnelle Eller covers agriculture, the environment and energy for the Register. Reach her at deller@registermedia.com or 515-284-8457.

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