In response to the pandemic, the White House and Congress are moving to pass legislation that would likely include enhanced unemployment benefits, free virus testing and additional funds for food assistance programs.

Complicating the Agriculture Department’s role, the agency also administers free and reduced-price meals at schools, thousands of which are closing. Mr. Perdue said his department is “working to ensure children who are affected by school closures continue to get fed.” It has granted waivers to California, Washington and Alaska that allows the states to serve meals to low-income children during school closures outside of a group setting while schools are closed. The waivers will be in place until June.

The House coronavirus package included a provision that would increase food-stamp benefits to parents who have children that cannot receive meals at school because of closures.

“Although it may be necessary to close schools, it is also imperative that we keep in mind that school meals are often the only meals some students receive daily,” said Representative Marcia L. Fudge, Democrat of Ohio and chairwoman of the House Agriculture Committee’s subcommittee on nutrition.

Ellen Vollinger, the food stamp director at the Food Research & Action Center, an advocacy organization, said the coronavirus outbreak presented a new challenge because it was a public health emergency and not a natural disaster.

“We know that low-income families have a lot of pressures on their budget, they are often trying to figure out how to pay for food, medicine, their rent, utilities and there is not a lot of extra room,” she said.

Medicaid could help poor Americans weather the pandemic, particularly some of the 27 million people lacking health insurance. Yet the Trump administration has not offered states the option of covering some of all of them during the outbreak, a move previous administrations made did during emergencies. President Trump’s emergency declaration could change that by allowing states to quickly receive certain waivers from the rules; such waivers could also streamline the often-burdensome process of enrolling people in Medicaid.