CHICAGO (CBS) — With one day left on a 72-hour deadline to reunite two Brazilian boys with their fathers, it’s still unclear exactly how the Trump administration will comply a federal judge’s order.

On Monday, U.S. District Judge Edmond Chang issued an order giving the federal government until 1:48 p.m. Thursday to reunite the boys, ages 16 and 9, with their fathers, who remain in federal custody – one in New Mexico and the other in Texas.

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At a hearing on Wednesday, attorneys for the Trump administration were unable to provide any details about how they plan to meet the deadline.

The federal government said it will comply with Chang’s order, but said their efforts remain very fluid.

The older boy was in court on Wednesday, and looked happy and relieved to know he would soon be back with his father.

The boys have been separated from their fathers for 48 days, and have been housed at a Heartland Alliance facility for immigrant children who either arrived in the U.S. without their parents, or were forcibly separated from their families at the border.

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Attorneys for the boys and their fathers have said both families, who are not related, tried to enter the country legally at the New Mexico border, seeking asylum, but were illegally turned away by Immigration and Customs Enforcement agents who told them the border was closed.

The fathers later were arrested and forcibly separated from their sons.

The federal government has two options for the boys and their fathers: keep them together in a family detention center, or release them while their asylum cases proceed.

While Chang had the authority to order the Trump administration to reunite the fathers and their sons, he did not have the power to order the fathers released.

Attorneys for the boys said the 16-year-old and his father were marked for death by organized crime figures in Brazil, and the 9-year-old and his father had been threatened by a loan shark.

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If the government does not meet the deadline to reunite the boys with their fathers, another hearing has been scheduled for Friday.