The leader of the nation’s premier public health agency Friday amplified President Trump’s call for schools to reopen, releasing new documents edited by the White House that gloss over risks and extol the benefits of in-person learning.

Still, Robert Redfield, director of the Centers for Disease Control and Prevention, said there should be exceptions for “hot spots,” and he used a metric that would include parts of at least 33 states.

The mixed messaging was another indication of how public health officials at the CDC have been squeezed between Trump’s demand for a normal school year and an out-of-control virus.

The new CDC guidelines, released late Thursday under pressure from the White House, detail at length the academic and other benefits to children of in-person learning, as well as the economic impact of allowing parents to work. They say little about the risks of reopening.

“Opening up our schools again is the best thing for our kids. It’s also the best thing for working families,” Vice President Pence said Friday at Marian University, a private Catholic school in Indianapolis. He praised the new guidelines as helping school districts figure out how to reopen safely.

On Friday, Redfield told reporters the new documents were cleared by the White House, and officials familiar with them, speaking on the condition of anonymity because they were not authorized to speak publicly, said at least one was substantially edited by White House officials. The opening statement was written at the Department of Health and Human Services, Redfield said.

The guidance does not carry the force of law, and it’s unclear how much influence it will have with school systems. Many large districts, including those in Atlanta, Los Angeles and New York, have already said they will not return to fully in-person school when classes resume. Some school districts had planned a hybrid system, with children in school buildings some of the time, but have retreated and are planning to begin the year fully remote.

St. Andrew’s Episcopal School, the Maryland private academy that Trump’s 14-year-old son Barron Trump attends, told families this week they should prepare for an all-distance or hybrid-learning model in the fall.

Polling shows a majority of parents favor delaying the opening of school doors, despite the downsides. Teachers unions, too, are warning that adults in school buildings are at risk of infection, even though children do not typically get particularly sick from covid-19, the disease caused by the novel coronavirus.

The debate over schools came as Friday’s covid-19 death count in the United States was at least 1,125, the fourth day in a row when it surpassed 1,000, according to a Washington Post analysis of numbers reported by state health departments.

The number of new cases leveled off or dropped this week in some of the states that have recorded marked increases in previous weeks, including Texas, Florida, Arizona and North and South Carolina. But it was unclear how much of the drop in reported cases is because of backlogs in testing that have residents in some states waiting a week or more for their results.

A senior administration official said the White House expects public mood on schools to shift as officials make their case for how students will be hurt if schools do not reopen.

Rep. Robert C. “Bobby” Scott (D-Va.), chairman of the House Education Committee, replied it is ridiculous to debate the benefits of in-person schooling because nobody questions them. The issue is whether it can be done safely, he said.

“Obviously it’s much better to have in-person instruction if it can be done safely,” Scott said. “If you can’t do it safely, you shouldn’t do it at all.”

Leading public health experts — including some inside the administration — say schools must strike a balance.

“Opening the schools is not a simple decision. There are both benefits and risks,” said Erin K. Sauber-Schatz, lead on the CDC Community Interventions and Critical Populations Task Force for the covid-19 response.

Senior Trump administration officials have allowed there might be exceptions to opening schools but had not defined them.

On Thursday, Trump said schools may need to delay reopening in places that are “current hot spots,” and on Friday, Redfield echoed the thought. “In areas where there are hot spots, remote and distance learning may need to be adopted for some amount of time,” Redfield told reporters on a call to discuss the new guidelines.

Redfield was then asked for a definition of “hot spots.” He said it would include places where more than 5 percent of coronavirus tests come back positive. Looking county by county, he said “the majority of the nation” is not a hot spot.

Yet by his definition, large sections of the country are in fact hot spots.

Johns Hopkins University shows that over the past week, 33 states and Puerto Rico have “positivity rates” above 5 percent. In 12 states, the rate was more than 10 percent.

In Florida, only two counties have positive rates below 5 percent — Alachua County and Bay County, which together hold about 2 percent of Florida’s population.

In Arizona, only Greenlee County, the least populated jurisdiction in the state with 9,483 people, has a positivity rate at 5 percent. Florida and Arizona have overall positivity rates well above 10 percent.

Nationally, the positivity rate is 10 percent, the CDC says.

According to an unpublished report from the White House Coronavirus Task Force this week, 772 counties or parishes across the United States are “red zones,” meaning they have test positivity rates above 10 percent — double the metric Redfield set — and are weekly adding more than 100 new cases per 100,000 residents. That tally does not include Puerto Rico or D.C. There are just over 3,000 counties in the United States.

Given this variation, opening schools should be a local call, Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, said in a Post online broadcast.

“It depends on where you are,” he said. “We live in a very large country that is geographically and demographically diverse and certainly different in the extent to which there is covid virus activity.”

Schools in some places with low virus activity may be able to reopen without many adjustments, he said. In places where the virus is spreading, Fauci added, schools may have to take more drastic health precautions, such as hybrid learning and alternating schedules.

Fauci also suggested some states with rising cases, especially those in the South, go back to earlier phases of reopening. “You don’t necessarily have to go all the way back to a complete shutdown, but you certainly have to call a pause and maybe even a backing up a bit,” he said.

There were fresh signs Friday that the virus’s spread was continuing to affect life in the United States and abroad.

McDonald’s announced it would require masks in all of its fast-food restaurants beginning Aug. 1, following the lead of major retailers such as Walmart and Target. Gary Tibbetts, a veteran staff member of Rep. Vern Buchanan (R-Fla.), died of the virus, the congressman announced Friday. In Florida, officials announced a 9-year-old girl had died, the state’s youngest victim.

In Washington, lawmakers struggled to come to an agreement over a new pandemic aid package, even as millions of people are days away from losing unemployment benefits and a federal eviction moratorium is about to end. The GOP bill is expected to tie new aid to schools to whether they are reopening, something the White House is pushing.

This spring, the CDC issued guidance for how schools can operate safely, including recommendations for keeping students separated, such as placing desks six feet apart. Some school districts concluded they could not do that if all children were in the building.

As it became clear many school systems planned to conduct school completely or partly online this fall, Trump grew angry, believing the CDC guidance was pushing districts to these decisions and fearing closed schools would undercut his message that the nation is recovering from the coronavirus crisis. He promised new guidance would be forthcoming.

The new documents review, in considerable detail, the benefits of in-person schooling, including academics, social and emotional development, safety, nutrition and physical activity. They note that children from low-income families and those with disabilities face particular challenges learning from home.

“School closure disrupts the delivery of in-person instruction and critical services to children and families, which has negative individual and societal ramifications,” one of the documents concludes.

The CDC also released detailed guidance on mitigation of spread in schools, recommending widespread use of face coverings, social distancing and splitting students into “cohorts” that do not mix with others. Indoor exercise and large assemblies are discouraged; meals and music classes should be moved outside if possible.

Technical guidance details when and how to tell children to cover their faces, guides administrators on screening students for covid-19, and offers parents a list of prompts to help them decide whether to send their children to classes.

Josh Dawsey, Jacqueline Dupree and Lena H. Sun contributed to this report.