The Trump administration said in a court filing Monday that 463 parents of migrant children are no longer present in the United States, indicating that the number of mothers and fathers potentially deported without their children during the “zero tolerance” border crackdown could be far larger than previously acknowledged.

The progress report to U.S. District Judge Dana M. Sabraw cautioned the 463 cases are “under review,” meaning the filing was not a definitive tally of all migrant parents who have been deported while their children remain in U.S. government shelters.

Sabraw has issued the Trump administration a 30-day deadline — expiring Thursday — to quickly reunite as many separated families as possible, and last week he asked the government to clarify how many of the more than 2,500 parents eligible for reunions are no longer in the country. He also temporarily suspended deportations of families that have been reunited.