Democrats said they invited officials from the US Centres for Disease Control and Prevention, including director Robert Redfield, to testify at a hearing next Thursday but were rebuffed by the White House.

Bobby Scott, a Virginia Democrat who chairs the House Education and Labour Committee, called it alarming that the Trump administration would prevent CDC officials from appearing before the committee "at a time when its expertise and guidance is so critical to the health and safety of students, parents, and educators."

The administration's "lack of transparency does a great disservice to the many communities across the country facing difficult decisions about reopening schools this fall," Scott said.

A White House spokesperson said Friday that Dr. Redfield has testified on Capitol Hill at least four times over the last three months. "We need our doctors focused on the pandemic response," spokesperson Judd Deere said.

The decision to block Redfield's testimony recalled a similar action preventing Dr. Anthony Fauci, the nation's top infectious-disease official, from testifying before a separate House committee earlier this year. Fauci ended up testifying the following week before the Republican-controlled Senate and appeared before a House panel last month.

"The administration's strategy of prioritising politics over science has had a devastating impact on our country throughout this pandemic," Scott said. "It should not make that same mistake when it comes to reopening schools."

President Donald Trump has pushed to reopen schools as scheduled this autumn, arguing that most parents are anxious to see schools resume in-person classes. Trump says the decision in some areas to avoid doing so is more motivated by politics than by legitimate fears about the pandemic.

"They think it's going to be good for them politically, so they keep the schools closed," Trump said at a White House discussion on school plans last week. "No way. We're very much going to put pressure on governors and everybody else to open the schools."

He has threatened to withhold federal funding from schools that refuse to reopen.

Australian Associated Press