NEW YORK CNN  — 

New York City Mayor Bill de Blasio has told top brass at the city’s police department to stop arresting people who are caught smoking marijuana in public, according to a City Hall aide.

Currently, smoking in public can lead to arrest, while possession of small amounts of marijuana can lead to a summons.

This weekend, the mayor told the NYPD to issue summonses for smoking pot in public, instead of making arrests.

The NYPD has already begun a working group to evaluate its marijuana enforcement procedures and present its recommendations within 30 days, at the mayor’s request. The mayor made it clear this weekend that ending public marijuana smoking arrests is one of the changes he wants.

Any changes to NYPD’s policy on smoking in public would not take effect until the end of the summer.

NYPD Deputy Commissioner of Public Information Phil Walzak told CNN that the 30-day working group is already underway, and that the issue is “certainly part of that review.”

“The working group is reviewing possession and public smoking of marijuana to ensure enforcement is consistent with the values of fairness and trust, while also promoting public safety and addressing community concerns,” Walzak said.

Manhattan to end prosecution

De Blasio’s call to end arrests comes after both the the mayor and Manhattan District Attorney Cy Vance made big announcements about marijuana enforcement on May 15.

The mayor publicly called on the NYPD to come up with a plan to make changes to its marijuana enforcement policies in the next month, and Vance said he would end prosecution of marijuana possession and smoking cases, starting August 1.

Under the current policy in Manhattan, people are arrested, fingerprinted and have to appear in court.

Last year, cops in Manhattan arrested people for smoking or possessing small amounts of marijuana a little more than 5,500 times. A disproportionate number of those arrested were minorities.

“The dual mission of the Manhattan DA’s office is a safer New York and a more equal justice system,” Vance said Tuesday. “The ongoing arrest and criminal prosecution of predominantly black and brown New Yorkers for smoking marijuana serves neither of these goals.”

Vance, a Democrat who is in his third term, said his office was discussing with New York City police and de Blasio what exceptions there should be to the policy.

New York Police Commissioner James O’Neill said that, while the department doesn’t target minorities, “there are differences in arrest rates, and they have persisted going back many years, long before this current administration. We need an honest assessment about why they exist … “

O’Neill said NYPD officers should not make arrests that don’t impact public safety.

Under the DA’s new policy, people who violate the law would be issued summonses. The NYPD does this in cases where possession is the most serious charge a person would face, O’Neill said.

According to the New York State courts system, police officers issue a criminal court summons when certain laws have been violated. “Most people who receive a summons are not arrested and fingerprinted unless they fail to show identification,” its website says.

Marijuana is a Schedule I drug under federal law and is illegal. Some states, like New York, have decriminalized marijuana, making it a violation and not a crime to possess small amounts of cannabis.

Medical marijuana is legal under New York law, but cannot be smoked.

CNN’s Steve Almasy contributed to this report. Sonia Moghe reported from New York, Susannah Cullinane wrote from Auckland, New Zealand.