New York City Mayor Bill de Blasio says he is "absolutely considering" implementing a shelter-in-place directive for the city of at least 8 million people.

The order would permit New Yorkers to leave their homes only for food, medicine, and exercise.

What are the details?

During a CNN appearance Tuesday, de Blasio discussed COVID-19 plans for New York City.

"We're absolutely considering [shelter in place]," de Blasio said, referring to a similar and newly implemented plan in San Francisco. "We're going to look at all other options, but it could get to that for sure. It could get to that for the whole country."

On Monday, San Francisco Mayor London Breed announced that residents of San Francisco could leave their homes only for necessities over the coming three weeks. Any violations of the directive could be punishable by law. The order remains in effect until at least April 7 and prohibits gatherings of individuals outside the home, save for essential services.

France has issued similar orders, and residents must produce a form in order to leave their homes.

"We need to have our minds that this could be a crisis of at a minimum several months," de Blasio reasoned.

The mayor, who closed schools until at least April 20, added that it seems unlikely that schools will reopen at such a time.

"April 20 is when we're going to make our first attempt, but watching the trajectory, it's hard to imagine that's going to work," he admitted.