Dr. Robert Redfield, director of the Centers for Disease Control and Prevention (CDC), called masks the "most powerful tool" against the coronavirus.
"This is the greatest public health crisis that our nation has faced in more than a century," Redfield told "Good Morning America" on Wednesday. "If all Americans would embrace that [masks] as part of their personal responsibility to confront this outbreak, we could actually have a very significant impact on the outbreak that we're seeing across the country in the next four, six, eight, 10, 12 weeks."
But when it comes to the idea of a national mask mandate, Redfield said, "the issue is how to motivate all Americans to do that."
"Some governors have done it, obviously with mandates. Other governors have done it through example. I think our key is just to let the American public know how important this is," he said.
As the new school year nears, Redfield said he would "absolutely" be comfortable with his grandchildren heading back to their classrooms. Redfield added he only may have "some reservation" about his grandson with cystic fibrosis, "depending on how he could be accommodated in the school."
"I think it's really important to get our schools open," he said. "It's not public health versus opening the schools or the economy -- it's public health versus public health. I think there really are a number of negative public health consequences that have happened to our K-12 [students] by having schools closed."
"So it's so important now to work together with school districts to figure out how they can take our guidelines and operationalize them in a practical way and to do it in a way that is safe," he continued.