Keeping schools closed in the coming academic year is a greater risk to children's health than reopening them, even amid the COVID-19 pandemic, Robert Redfield, director of the U.S. Centers for Disease Control and Prevention said on Thursday.

Redfield said the guidelines the CDC has given on operating schools during the pandemic are designed to facilitate their reopening, and he would be "disappointed" if they were used as a rationale to keep them closed.

"I cannot overstate how important I think it is now to get our schools in this nation reopened," Redfield said at The Hill's Health Reimagined virtual summit. "The reason I push it is that I truly believe it's for the public health benefit of these kids."

On Wednesday, President Donald Trump blasted the CDC guidelines for schools to reopen as "impractical" and "expensive." Trump has called on schools to reopen, but there is no federal plan to coordinate the effort.

Vice President Mike Pence announced that the Centers for Disease Control and Prevention would be issuing new guidance next week "that will give all new tools to U.S. schools." The recommendations will keep students safe, he said, but "the president said today we just don't want the guidance to be too tough."

Redfield said on Thursday that none of the CDC's guidance on school reopening is inherently too costly for schools to handle.

He said he does not want schools to go "overboard" by failing to recognize that the virus is "relatively benign" for young people.

Trump made his threat a day after launching an all-out effort pressing state and local officials to reopen the nation's schools and colleges this fall. At a White House event Tuesday, health and education officials argued that keeping students out for the fall semester would pose greater health risks than any tied to the coronavirus.

Recently, U.S. colleges and universities have begun to announce plans for the fall 2020 semester amid the coronavirus pandemic. Harvard on Monday announced it would conduct course instruction online for the 2020-2021 academic year. 

Trump's administration has imposed a number of new restrictions to legal and illegal immigration in recent months as a result of the pandemic. Many international students will have to remake their academic plans if they have to leave the country given their classes might be taught online this fall. 

U.S. schools are scrambling to prepare for the upcoming academic year as the pandemic surges nationwide, topping 3 million confirmed cases.