Texas must move a large floating barrier that Gov. Greg Abbott placed on the river between the U.S. and Mexico this summer as part of the Republican’s escalating attempts to stop migrants from crossing America’s southern border, a federal judge ruled Wednesday.

U.S. District Judge David Ezra stopped short of ordering Texas to dismantle the wrecking-ball sized buoys on the Rio Grande but called them a threat to safety and relationships between the neighboring countries. His preliminary injunction instructs Texas, for now, to move the barrier out of the water and onto the riverbank by Sept. 15.

Ezra also cast doubt on Texas’ rationale for the barrier, writing that the state produced no “credible evidence that the buoy barrier as installed has significantly curtailed illegal immigration.”

The lawsuit was brought by the Justice Department in a rare instance of President Joe Biden’s administration going to court to challenge Texas’ border policies.

Texas officials said they would appeal.

“Today’s court decision merely prolongs President Biden’s willful refusal to acknowledge that Texas is rightfully stepping up to do the job that he should have been doing all along,” Abbott said.

Abbott invoked “invasion” powers to deploy aggressive new tactics starting last year. Texas’ use of dozens of bright orange buoys to create a barrier longer than a soccer field on a stretch of river where migrants often try crossing from Mexico is just one piece of his multibillion-dollar border mission known as Operation Lone Star. The state has also installed razor-wire fencing along the river and allowed troopers to arrest migrants on trespassing charges, among other things.

Ezra, an appointee of former President Ronald Reagan, rejected Abbott’s justification for all of Texas’ actions.

“Under this logic, once Texas decides, in its sole discretion, that it has been invaded, it is subject to no oversight of its ‘chosen means of waging war,’” Ezra wrote. “Such a claim is breathtaking.”

In challenging Texas’ use of the buoys, the U.S. Justice Department accused the state of putting a barrier on the international boundary without permission. The Biden administration also said the water barrier raised humanitarian and environmental concerns.

“We are pleased that the court ruled that the barrier was unlawful and irreparably harms diplomatic relations, public safety, navigation, and the operations of federal agency officials in and around the Rio Grande,” Associate Attorney General Vanita Gupta said in a statement.

Texas installed the barrier near the border town of Eagle Pass by putting anchors in the riverbed. Eagle Pass is part of a Border Patrol sector that has seen the second-highest number of migrant crossings this fiscal year with about 270,000 encounters — though that is lower than it was at this time last year.

The Biden administration has said illegal border crossings declined after new immigration rules took effect in May as pandemic-related asylum restrictions expired.

Like other pieces of Operation Lone Star, the buoys pick up where former President Donald Trump left off. Plans for the same water barrier were in the pipeline in 2020, according to Mark Morgan, who at the time was the acting commissioner of U.S. Customs and Border Protection.

Morgan said the plans were scrapped after Biden took office. He called the barrier a “water wall” and said it was intended to be used as a stopgap in sections of the border where fences were not yet built or were impractical.