"Well, a scarf's not going to be as good as a surgical mask and that won't be as good as a N95 mask. But there's a re-thinking around masks, in part because we realize that the virus doesn't go deep in your lungs," Oz told host Sean Hannity. "It probably inserts itself right at the very tip of your nose.
"Imagine little doors there, which are where the cells' ... receptors can accept the virus. The virus is a key and it unlocks those doors and goes in," he added. "Older people have more of those doors than younger people. That's why they get more of the infection, we believe."
"Wearing of any kind of facial covering could... block the larger droplets from getting into your nose," Oz went on. "So although culturally, we've had an aversion to wearing masks, certainly if you're sick, you should wear something over your face, getting a covering of some type to block the fluid."
Earlier Thursday, de Blasio urged New Yorkers to cover their nose and mouth when they leave the house, reversing previous guidance that said only those who are sick or caring for the sick should wear masks.
“We’re advising New Yorkers to wear a face covering when you go outside and near other people,” de Blasio told reporters. “It can be a scarf, it can be something you create at home, it can be a bandana.”
"The problem with cloth masks [is it] doesn't really protect you as well as you'd like to," Oz said. "You get a false sense of security, and if you play with it all the time, you actually touch your fingers to your eye. It's better than nothing but not a ton better than nothing."
Hannity also pressed Oz on why New York state still has restrictions in place on prescribing hydroxychloroquine. Under an executive order issued by Gov. Andrew Cuomo last week, doctors are prohibited from prescribing the anti-malarial drugs outside of state-approved clinical trials or Food and Drug Administration-approved uses.
"In China, they have a randomized trial. Everyone says it's very small, but ... I say the opposite. Even despite the small numbers, they got statistical, significantly improved results with reduction of fevers, reduction of the cough, improvement of CT scans showing less pneumonia, significant statistically, [a] less than 1 in 100 chance in two of those cases that it could just be random," Oz said.
"So even with a small number, we're seeing evidence we need a large trial. Everyone agrees with that."
Fox News' Morgan Phillips contributed to this article.