SAN FRANCISCO (AP) " A civil liberties group is suing the Trump administration in San Francisco over a policy that requires green card holders to pass a background check before they can start military service.

The American Civil Liberties Union said in the federal lawsuit filed Thursday that the U.S. Department of Defense is discriminating against permanent residents. The department announced the new policy in October 2017. Green card holders, like U.S. citizens, could previously report for basic service while their background checks were pending.

Defense Department spokesman Johnny Michael said the department is unable to discuss pending litigation.

The lawsuit names two permanent residents as plaintiffs, Jiahao Kuang and Deron Cooke. The ACLU says they enlisted in the military last year, but they have no idea when they'll be allowed to serve.