The Trump administration said Thursday that 57 of the 103 migrant children under five who were separated from their parents at the border had been reunited—and it would not be reuniting the 46 others, the Washington Post reports.

A federal judge had given the administration until Tuesday of this week to reunite all separated children under five years old, with a deadline of July 26th for the rest of the children.

"Throughout the reunification process our goal has been the well-being of the children and returning them to a safe environment," wrote Secretary of Health and Human Services Alex Azar, Secretary of Homeland Security Kirstjen Nielsen, and Attorney General Jeff Sessions in a joint statement.

Immigration officials provided a litany of reasons as to why the remaining 46 children were ineligible for reunification—namely parents with criminal histories, parents who were in custody or had been deported, or health reasons, Reuters reports.

The American Civil Liberties Union sued earlier this year to force the government to reunite migrant families. Lee Gelernt, deputy director of the ACLU's Immigrants' Rights Project, said in a statement that the organization would decide by the end of the day "what remedies to recommend to the court for the non-compliance."