The lawsuit asks the court to immediately end a number of laws and ordinances it says thwart federal immigration authorities.

The U.S. Justice Department sued the state of Illinois and city of Chicago on Thursday, accusing the Democratic strongholds of unlawfully interfering with Republican President Donald Trump's crackdown on illegal immigration and seeking a court order blocking so-called sanctuary laws.

Local law enforcement agencies play a limited role in immigration law, but that might change during Trump's promised mass deportation operation.

The U.S. Department of Justice sued Illinois and the city of Chicago on Thursday, accusing them of impeding the Trump administration's immigration enforcement policies and seeking a court order sweeping aside so-called sanctuary laws.

The federal lawsuit is the first by Trump's Justice Department against states or municipalities that have sanctuary city policies.

President Donald Trump’s administration went to court Thursday to challenge sanctuary policies in the state of Illinois, Cook County and the city of Chicago that limit the powers of state and local police to assist federal law enforcement on immigration-related matters.

The suit asserts that sanctuary laws in Chicago, Cook County and Illinois have obstructed federal efforts to enforce immigration policy.

Federal officials are asking a judge to bar the Illinois, Chicago, Cook County and the Cook County Sheriff from using local laws that protect migrants to hamper law enforcement.