(CNN)Attorneys are still trying to reach the parents of 368 migrant children who had been separated at the US-Mexico border under the Trump administration, down from 391 last month, according to a federal court filing Wednesday.
The filing from the Justice Department and the American Civil Liberties Union is part of an ongoing effort to identify and reunite families three years after the "zero tolerance" policy was created.
Since May, the parents of 23 of those children whose whereabouts were previously unknown have been found, according to Wednesday's filing.
Under then-President Donald Trump's "zero tolerance" immigration policy, border officials separated at least 2,800 children from their parents, according to government data. Officials later found that more than 1,000 children had been separated from their families before Trump's policy went into effect in 2018. The latest court filing is specific to those families separated under the Trump administration.
The Biden administration recently reunited 24 families who had been separated at the US-Mexico border under the "zero tolerance" policy as part of the administration's interagency task force efforts.
The task force has been engaging with groups that are in touch with families and carefully planning their return, taking into account past trauma, Ann Garcia, an attorney who's been working on assisting separated families with legal and social needs, previously told CNN, noting that some parents are nervous about encountering US Customs and Border Protection again since their last encounters with agents resulted in their children being taken from them.
As part of the effort, the Department of Homeland Security is establishing a process for accepting parole requests, the Department of Health and Human Services is working on facilitating services to support families and the State Department is developing a streamlined system for processing in-country travel document requests. The Justice Department is involved in related settlement negotiation efforts.
Immigrant advocacy groups have urged the administration to move faster to reunite families, some of whom have been separated for more than three years.
But a senior DHS official told CNN earlier this month, "We chose intentionally to start slow, so we can go fast later."
"We need to make sure that families have a place to go when they get here," the official said. "There's a review of the cases and preparation for travel."