The Trump administration said 463 immigrant parents separated from their children under the government’s zero-tolerance policy for illegal border crossers may have been deported.

In court Tuesday, Justice Department lawyers said they are individually reviewing those cases to see how many parents were deported or voluntarily left the country without their children.

U.S. District Judge Dana Sabraw in San Diego said that uncertainty is “a deeply troubling reality of the case” and that the government needs to account for those cases as quickly as possible.

During the Tuesday court hearing, American Civil Liberties Union lawyer Lee Gelernt called the situation on the ground “a mess” as lawyers try to assist with reunifications. Many parents, he said, “have no idea what’s happening.”

Justice Department lawyer Scott Stewart strongly disputed that characterization and said there has “been a tremendous effort to reunify.”