Federal prosecutors have sued New York City to speed up reforms at Rikers Island.
The lawsuit was filed Thursday to address what a Justice Department investigation found was a culture of violence against young inmates, according to The Associated Press.
Mayor Bill de Blasio visited the Rikers Island jail complex December 17 to announce the end of solitary confinement for 16- and 17-year-old inmates. It was de Blasio's first trip to Rikers as mayor.
The end of solitary confinement was one of 73 recommendations made by federal prosecutors to curb the violence.
According to the AP, Attorney General Eric Holder and Manhattan U.S. Attorney Preet Bharara wrote in court papers that despite four months of negotiations with the city, federal prosecutors "have been unable to reach agreement as to lasting, verifiable and enforceable reforms."
Information from the Associated Press was used in this report.