New York City Mayor Bill de Blasio is proposing a plan to open the nation’s first supervised injection facilities in Manhattan, Brooklyn and the Bronx as part of an ongoing effort to combat opioid addiction, The New York Times reports. 

The sites — which provide a space for drug users to inject drugs under medical supervision and with overdose-reversing drugs on hand — are widespread in cities across Canada and Europe. But none exist in the United States, largely because they may violate federal law. Mayor de Blasio joins leaders in San Francisco, Philadelphia, and Seattle who are also seeking to open such sites within the next two years to help combat overdose-related deaths and cut back on the number of new hepatitis C virus (HCV) and HIV infections. 

Last year, New York City saw 1,441 overdose deaths. In order to pass an ordinance to legally open a safe injection site, De Blasio must gain the support of several district attorneys as well as the New York State Department of Health, which answers to New York Governor Andrew Cuomo. The city asserted its intention in a letter sent to the state last week. But it is unclear whether Cuomo, who is up for re-election this year, will approve of the plan.

According to the letter, the city hopes to open four sites following a six- to 12-month period of advocate outreach in the communities where they’d be located. The so-called Overdose Prevention Centers would operate as pilot programs for a year before being analyzed for their success. Each site would have trained staff on hand to administer medications, such as naloxone, to help reverse overdoses. The sites would also employ social workers to help steer drug users into drug treatment programs.

Each site would be financed and run entirely by nonprofit groups, not the city. Some may be housed within community organizations that already operate needle exchanges. So far, sites have been proposed in Washington Heights and Midtown West in Manhattan, Longwood in the Bronx and Gowanus in Brooklyn.

De Blasio’s proposal arrives amid pressure from activists who have have staged multiple demonstrations at City Hall demanding them.