The move by District Attorney Cyrus Vance Jr. came the same day that Mayor Bill de Blasio promised that the city's police department would overhaul its marijuana enforcement policies in the next 30 days. Brooklyn's district attorney also said he would scale back prosecutions.

"We must and we will end unnecessary arrests and end disparity in enforcement," de Blasio said at a conference of the Center for American Progress in Washington, D.C.

Vance said that his office will stop prosecuting marijuana possession and smoking cases starting Aug. 1 except for a few cases involving "demonstrated public safety concerns."