The Trump administration is suing Chicago over what are known as sanctuary laws. The administration claims the nation’s third-largest city “thwarts” federal efforts to enforce immigration laws.

The lawsuit comes as Chicago mayor Brandon Johnson is expected to testify before the House Oversight Committee next month.

The U.S. Department of Justice filed a lawsuit Thursday against Chicago, Cook County and the state of Illinois, accusing officials of interfering with immigration enforcement efforts. The suit comes on the heels of a federal judge blocking President Donald Trump’s executive order preventing the children of migrants without legal status from receiving birthright citizenship for the second time this week.