Hundreds of migrant parents are no longer in the US, government lawyers said, ahead of a deadline to reunite families.
Administration lawyers told a federal court more than 450 parents had gone, with the government unable to say if they had been deported.
The Trump administration recently halted its policy of separating migrant families at the border with Mexico.
A court ordered that it must now reunite children with their parents.
On Tuesday he said the government was on track to complete the task by that deadline and praised the government's "remarkable achievement" of returning the majority of children rapidly.
However, he said the separations and the realities of the case remain "deeply troubling".
In a court filing, the administration said 463 parents had left the country, although it did not say if this was voluntary or not.
The news comes amid reports that US immigration authorities are telling migrant parents to sign voluntary deportation forms in order to see their children.
Lawyers for the government also said the figure of 463 parents was "under review", and the final tally could be different.
According to a filing by the government and the American Civil Liberties Union (ACLU) on Monday, at least 879 parents had so far been reunited with their children.
Under a separate court-imposed deadline earlier in July, most migrant children under five years old have been returned to their parents.
Hundreds of children, however, remain separated.
On Tuesday the ACLU filed a further motion to delay deportations of any parent for a week after being reunited with their children.
Parents with a final removal order have 48 hours to decide if they want to leave the US as a family or let their children stay and seek asylum. The ACLU want parents to have more time to consider legal options.
But US government lawyers urged the court to allow faster deportation, saying any delays keep migrants in detention longer and citing the cost of housing families.
Judge Sabraw delayed a decision on the ACLU motion until Friday.
- 4 die as bus carrying choristers plunges into a river
- Commercial drivers to embark on indefinite strike from Monday
- Teacher union to demonstrate on December 15 over laptop deductions
- Mourinho fumes after Roma defeat: ‘There’s a reason we earn a lot more than journalists’
- ‘Legislative hooliganism’ affecting Parliament – Kweku Baako
- Trump social media firm raises $1bn from investors
- I don’t like being a role model and never tried to be the best – Messi
- Belgian zoo hippos test positive for Covid-19
- Kumasi Habitat Fair: Patrons get their land disputes resolved
- Akufo-Addo temporarily bans Ministers, deputies from international travel
Indonesia Consulate in Ghana commiserates with Indonesia volcano victims
Army Col. Edward Shames, the last remaining member of World War II’s ‘Band of Brothers,’ dies at 99
I’m always fair when presiding over matters of Parliament – First Deputy Speaker
JoyNews’ Opoku Gakpo calls for increased investment in smallholder agriculture
Forestry Commission lifts ban on hunting in forests
Playback: The Probe discusses dramatic twists and turns in Parliament over 2022 budget
African Amputee Football Cup of Nations: Sports Ministry to facilitate return flight of stranded champions
Ghana Oil and Gas Award: Full list of 2021 winners
There was no proper quorum formed for Bagbin’s rule – Lawyer
Acting Speaker can’t form a quorum or vote – Prof Abotsi
Panelists at AGRA Farmers’ Day Event call for better collaborations to improve agriculture
Akufo-Addo temporarily bans Ministers, deputies from international travel
Commercial drivers to embark on indefinite strike from Monday
Marince Omario, Black Sherif, Spacely others thrill fans at maiden ‘Gbonyo Party’
Teacher union to demonstrate on December 15 over laptop deductions