The Trump administration argued in a series of court filings late Thursday that it may not be able to fully comply with a federal judge's order to reunite nearly 3,000 children separated from their parents by the end of the month.

The administration must reunite all children under age 5 by Tuesday, and all other minors by July 26. But government lawyers and an Immigration and Customs Enforcement director who has been overseeing the reunification process said there is too much work to do and too many questions about the judge's order to meet his strict deadlines.

"Defendants have dedicated immense resources and effort to reunifying families, and personnel at the highest levels of the agencies have been involved in implementing the Court’s directives," according to a filing by the Department of Justice. "To fully implement these plans, however, Defendants may need clarification on or relief from ... the Court's deadlines."

The requests were filed on the same day that Health and Human Services Secretary Alex Azar held a conference call where he assured reporters that the administration would reunite all the children that had been separated. Azar criticized the ruling, but vowed to meet the court-imposed deadlines.

"We will comply with the artificial deadlines established by the courts," he said.

District Judge Dana Sabraw, the judge who issued the order to reunite all the separated families, will hold a court hearing Friday afternoon to address the requests for clarification from the government, and concerns raised by immigration advocacy groups over the entire process.