Landrieu certified that the city was in full compliance in April, after a DOJ letter sent to officials in New Orleans, Sacramento, Chicago, Philadelphia, Las Vegas, Miami, Milwaukee, and NY threatening penalties against any city operating as a "sanctuary city".
Philadelphia police policy forbids officers from asking about anyone's immigration status; city officials have said that when officers inadvertently learn about someone's immigration status, that information will make it into a police report only when that person is suspected of a crime.
City and county officials did not immediately say how they would respond to the letters.
The Trump administration has taken a hard stance against so-called "sanctuary cities" like Philadelphia, claiming they leave violent criminals on the streets.
Attorney General Jeff Sessions said in a written statement that sanctuary cities "adopt the view that the protection of criminal aliens is more important than the protection of law-abiding citizens and of the rule of law".
Mayor Kenney said Philadelphia welcomes immigrants and supports its immigrant communities.
Lavrov says Tehran abides by all commitments on Iran nuclear deal
Second, Trump could call for greater non-nuclear sanctions on Iran as it seeks to punish the regime without violating the deal. The agreement contains specific restrictions on Iran's nuclear program that will expire after predetermined periods of time.
As he has repeated following similar threats, Landrieu says NOPD's policy - which followed extensive review with ICE under the federal consent decree - is in "full compliance" with the feds and has argued that the threats made by the Trump administration against the city are unfounded and politically motivated. Additionally, the Justice Department said subsequent investigations found Miami-Dade County, Fla., and Clark County, Nev., where Las Vegas is located, were already in accordance with federal immigration law, though previously they had been listed otherwise.
In addition, Philadelphia is suing over other new requirements for policing grants that Sessions imposed on cities in July, aimed at punishing sanctuary cities.
It added that the four cities have until October 27 to show they are complying with other, long-standing federal law, including a almost 20-year-old statute that says cities can't hinder information sharing with immigration agents. In the letter, the department did not specify what would happen if the city failed to do so.
Chicago filed a lawsuit in August and a federal judge sided with the city, issuing a preliminary injunction blocking the federal government from pulling crime-fighting grants.
The department also wrote that the city's policy of not sharing the immigration status of victims of crime is also in violation of the law. The Justice Department is appealing the ruling, according to the Chicago Tribune.
Both the city and the county have identical ordinances on the books preventing local law enforcement from "expend (ing) their time responding to (Immigration and Customs Enforcement) inquiries or communicating with ICE regarding" individuals' incarceration status or release dates while on duty.