Lawyers appointed to reunite migrant families separated at the U.S.-Mexico border as a result of a Trump-era immigration policy say they’ve found the parents of more than 100 children over the past month, NBC News reports.

In 2018, the Trump administration instituted a “zero tolerance” immigration policy that called for the criminal prosecutions of adults illegally crossing the southern border. The move resulted in the separation of thousands of families.

The policy was abandoned by the summer of 2018, and a federal judge assigned a team of lawyers to search for hundreds of missing parents following a lawsuit brought by the American Civil Liberties Union (ACLU).A status report filed by the team of lawyers Wednesday said they have found the parents of 105 children in the past month, but are still searching for the parents of 506 children.

Parents of 322 of the children have likely been deported, making efforts to find them more challenging. Lawyers say many agreed to be deported without their children to allow them to claim asylum and stay in the U.S.

President Biden earlier this month signed an executive order establishing a new task force to identify and reunify separated families. The task force is chaired by Department of Homeland Security Secretary Alejandro Mayorkas.

“Defendants believe that the work of the Task Force will resolve many—if not all—outstanding issues in this litigation, and Defendants look forward to working with Plaintiffs with that goal in mind,” the lawyers’ filing states.