Mayor Bill de Blasio finally announced plans Tuesday afternoon to open streets for pedestrians in a bid to reduce parks crowds during the coronavirus pandemic — two days after Gov. Andrew Cuomo gave him 24 hours to do so.

Starting Thursday, city officials hope to close “up to two streets per borough” to traffic to create alternative recreational space to city parks, which have been crowded despite concerns about the spread of COVID-19, de Blasio said at a City Hall press conference.

The open streets will be enforced by NYPD.

“The ground rule was [NYPD] had to be able to enforce it, unless it was going to be counterproductive,” he said. “People do need space to exercise.”

Officials are still considering whether to shutter playgrounds; the mayor said a decision would be made by the end of Saturday.

“We may get to the point in just days where we have to close the playgrounds for the duration of this crisis. It’s not something I want to do, but it’s something I’m ready to do,” he said.

On Sunday, Gov. Andrew Cuomo said New York City had 24 hours to come up with a plan to lighten the load on parks like Prospect Park in Brooklyn, where the governor paid a surprise visit on Saturday.

More information on the street closures will be available later in the week, the mayor said.

The mayor also announced that alternate side parking rules — suspended since last week — will continue to be suspended at least through the end of the month.