The Trump administration is suing Chicago over what are known as sanctuary laws. CHICAGO — The Trump administration sued Chicago on Thursday alleging that 'sanctuary' laws in the nation's third-largest city “thwart" federal efforts to enforce immigration laws.

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.

The Trump administration sued officials in Illinois, Chicago and Cook County on Thursday over policies that limit cooperation with federal immigration enforcement authorities, accusing them of obstructing its immigration crackdown.