New York City Mayor Bill de Blasio warned residents that he was considering imposing an order to shelter in place as the city copes with the spread of the coronavirus.

De Blasio, a former 2020 Democratic candidate for president, said on Tuesday that he was considering the action and that a decision may be made in the next couple of days, according to the Wall Street Journal. The order would direct millions of people to stay in their homes as much as possible for a certain period of time.