The Department of Justice has sent letters to Philadelphia and eight other jurisdictions, threatening to withhold funds for failing to cooperate with federal immigration officials.
The notifications were sent Friday to officials in Philadelphia, as well as Chicago, New Orleans, Las Vegas, Miami, Milwaukee, New York, Cook County, Ill., and the California Department of Corrections and Rehabilitation.
The letters, posted online by the Los Angeles Times, asked for proof that the cities are cooperating with immigration enforcement and indicated that the jurisdictions could be at risk of losing grants.
Philadelphia's letter, addressed to Mayor Kenney, warns that the city "is required to submit documentation" to the Justice Department affirming its compliance with a federal law that prohibits jurisdictions from restricting communications with the Immigration and Naturalization Service about individuals' immigration statuses.
That documentation must be received by June 30.
"Failure to comply with this condition could result in the withholding of grant funds, suspension or termination of the grant, ineligibility for future [Office of Justice Programs] grants or subgrants, or other action, as appropriate," the letter said.
The letters come after Attorney General Jeff Sessions warned last month that so-called sanctuary cities were at risk of losing funds for failing to comply with federal immigration law.
Philadelphia police officers are barred from asking about the immigration status of people with whom they come in contact.
The other cities that received letters also have policies that restrict the ability of local police and jails to hand people who are in the country illegally over to federal immigration authorities.
Last month, mayoral spokeswoman Lauren Hitt called Sessions' threat a "direct attack on public safety" and said the city had no plans to change its sanctuary policy.
Some experts do not expect Philadelphia and other cities to have difficulty complying with Friday's letters because it only requires that local law enforcement not impede communication between local and federal authorities, according to the Wall Street Journal.