SEATTLE — A lawsuit by 17 states challenging President Donald Trump's separation of migrant families at the Mexico border has been transferred to a California courtroom where a federal judge is already overseeing several related cases.

Washington, California, Massachusetts and other states led by Democratic attorneys general filed the lawsuit in U.S. District Court in Seattle. U.S. District Judge Marsha Pechman said Wednesday that transferring the case would be more efficient.

U.S. District Judge Dana Sabraw in San Diego ordered the administration in late June to reunite more than 2,500 children with their parents. Several hundred children have yet to be reunited, in some cases because their parents have been deported.

Pechman said she didn't want any orders she might issue to conflict with decisions by Sabraw.