A federal judge issued a preliminary injunction on Thursday blocking Florida from further expanding the "Alligator Alcatraz" immigration detention center built in the middle of the Florida Everglades.
U.S. District Judge Kathleen Williams' injunction formalized the temporary halt she had ordered two weeks ago.
Witnesses continued to testify over multiple days in a hearing to determine whether construction of the facility should stop until the case is decided.
Advocates have argued that the expansion of the facility violated environmental laws.
Williams said she expected the number of detainees in the facility to dip within 60 days through transfers to other facilities, and that fencing, lighting and generators should then be removed. She said the state and federal defendants cannot bring anyone other than current detainees at the facility onto the property.
The order does not halt modifications or repairs to existing facilities, which the judge said are "solely for the purpose of increasing safety or mitigating environmental or other risks at the site."
The preliminary injunction includes "those who are in active concert or participation with" the state of Florida or federal defendants or their officers, agents or employees, she wrote.
State officials failed to sufficiently explain why the facility needed to be in the middle of the Florida Everglades.
"What is apparent, however, is that in their haste to construct the detention camp, the State did not consider alternative locations," Williams said.
Florida officials criticized the ruling on Thursday.
"Just this week, a judge in the same district as Judge Williams refused to hear a case because the Southern District of Florida was the improper venue for suits about Alligator Alcatraz," Jeremy Redfern, a spokesperson for the Florida attorney general's office, said in a statement to Fox News. "Once again, she oversteps her authority, and we will appeal this unlawful decision."
The Associated Press contributed to this report.