A federal court dismissed a lawsuit filed by the Trump administration against New York City’s sanctuary laws on Thursday as the city’s mayor, Zohran Mamdani, heralded the loss, saying he would not allow the government to “use fear to divide our city”.

The ruling marks the latest defeat for the federal government, as it sues cities and states over legal protections for immigrants. Federal courts in Los Angeles, Chicago and Minnesota have thrown out similar lawsuits over the last two years.

The US district judge Ramón E Reyes Jr affirmed in Thursday’s ruling that “there is nothing within federal law that obligates states to participate in federal immigration enforcement or compels states to comply”. He argued that the city’s agencies couldn’t be forced into using their resources to enforce civil immigration laws, and rejected the Trump administration’s argument that local officials were illegally obstructing its immigration agenda.

Sanctuary laws limit cooperation between local officials and the federal government when it comes to civil immigration enforcement. In New York City, there are limits on the police department’s ability to hold immigrants for Immigration and Customs Enforcement (ICE) through detainer requests, and on general information sharing between the agencies.

Mamdani celebrated the ruling. “The federal government came to court seeking to force New York City to turn its public servants into deportation agents and divert our resources toward carrying out ICE’s cruel agenda,” he said in a statement. “The court made clear that the federal government has no standing to bring this case and cannot commandeer our city workers to do its bidding. Our city belongs to all of us, and we will not abandon our neighbors to satisfy an inhumane, xenophobic agenda.”The justice department did not immediately respond to a request for comment, but had said in its initial complaint that the New York’s sanctuary policies resulted in criminals being released into the city who should have been held for immigration removal.

New York City has recently been facing increased scrutiny over its sanctuary laws. Earlier this month, an agent with ICE shot 28-year-old Oscar Belgal while he had his child in the back of his car, before the agency detained him.

The NYPD eventually arrived on the scene and was criticized for its heavy-handed response to protests, which included shoving Darializa Avila Chevalier. The Democratic congressional candidate said the police’s conduct violated “the spirit, if not the letter” of the city’s sanctuary laws.

Jessica Tisch, the New York City police commissioner, said during a Thursday press conference that the NYPD was not involved in the federal immigration operation prior to the shooting. Tisch said officers arrived for the purpose of preserving evidence.

While the federal government lost its case in New York City, it has been successfully pushing a major expansion of a program that formalizes relationships between federal immigration enforcement and local police departments. These 287 (g) contracts, as they are known, deputize local officers to enforce federal immigration law. New York City does not have such a contract but the ACLU has tracked the rapid expansion of the program across the country during the second Trump administration.

Still, local immigration advocates are relieved that the federal court stepped in to protect the city’s sanctuary laws. They had explained in an amicus brief in the case that the city’s sanctuary laws serve a key “trust-building function” and encourage immigrants to apply for public benefits, visit hospitals and seek assistance from police without fear of arrest.

They wrote: “The city’s decision not to participate in federal civil immigration enforcement efforts has particular gravity during this administration, which has pursued immigration enforcement on a massive scale in an often lawless, violent and gratuitously cruel manner.”