Schools 'must fully open': White House

The CDC has made a number of recommendations for schools, including testing for COVID-19, dividing students into small groups, serving packaged lunches in classrooms instead of cafeterias, and minimizing sharing of school supplies.

It has advised that seats be spaced at least six feet apart and that sneeze guards and partitions be put in place when social distancing is not possible.

Administration officials said local leaders would tailor their decisions on how schools reopen.

"Ultimately it's not a matter of if schools should reopen, it's simply a matter of how. They must fully open," Education Secretary Betsy DeVos said.

President Trump, a Republican who is seeking re-election in November, accused Democrats of wanting to keep schools shut for political reasons and threatened to cut off federal funding to schools that do not reopen, despite a surge in coronavirus cases.

"I disagree with @CDCgov on their very tough & expensive guidelines for opening schools. While they want them open, they are asking schools to do very impractical things. I will be meeting with them!!!" Trump said on Twitter.

States are responsible for primary and secondary education under the U.S. Constitution, but some have been holding off on deciding when and how to open schools, concerned about the resurgence of coronavirus across the country.