The U.S. Department of Justice sued the state of Texas and its controversial Republican Gov. Greg Abbott on Monday over its placing of floating barriers in the Rio Grande River as a way of stopping migrants from crossing into the U.S. but that the Biden administration calls a threat to public safety.

“We allege that Texas has flouted federal law by installing a barrier in the Rio Grande without obtaining the required federal authorization,” said Associate Attorney General Vanita Gupta.  “This floating barrier poses threats to navigation and public safety and presents humanitarian concerns.  Additionally, the presence of the floating barrier has prompted diplomatic protests by Mexico and risks damaging U.S. foreign policy.”

Filed in federal court in Austin, the lawsuit alleges that Abbott violated the law by building the water buoys in the Rio Grande River without authorization, creating an obstruction in U.S. waters.

The DOJ is looking to require Texas officials to remove the barrier at the state’s expense. According to the suit, structures placed in the Rio Grande require approval from the U.S. Army Corps of Engineers, which Texas never tried to obtain or received such a permit.

“The Rivers and Harbors Act is clear in prohibiting the placement of any unauthorized barriers or obstructions in the Rio Grande and other navigable waters of the United States,” said Assistant Attorney General Todd Kim of the Justice Department’s Environment and Natural Resources Division. “We intend to seek the appropriate legal remedies, including the removal of such obstructions in the Rio Grande.”

For Abbott, the lawsuit was expected after the DOJ sent a letter to Abbott last week informing the governor of their plans to sue the state if he did not remove the barricade, which is made up of large buoys to deter migrants coming from Mexico. 

The department cited in its letter the “unlawful construction of a floating barrier in the Rio Grande River,” as well as asserted it could impede the federal government’s “official duties.” 

Abbott responded in a letter early Monday that he would not comply with the DOJ’s request. The state had until Monday to comply. Miles of barriers using barbed wire and buoys in the river near Eagle Pass were set up earlier this month. 

“To end the risk that migrants will be harmed crossing the border illegally, you must fully enforce the laws of the United States that prohibit illegal immigration between ports of entry,” Abbott said in the letter.

A Justice Department spokesperson said last week that officials were also looking into recent allegations that Texas state troopers were ordered to push migrants back into the water, including children.

White House press secretary Karine Jean-Pierre denounced Abbott’s actions to reporters on Monday, calling them “dangerous and unlawful."

“We actually saw the president’s plan working and what you see the governor doing is dangerous and unlawful,” Jean-Pierre told reporters. “It’s actually hurting the process. It’s hurting the process of what we’re trying to do.”

She later said, “He’s literally operating in bad faith.”

“Governor Abbott is not moving forward in good faith. He’s just not,” she said. “The one person that is sowing chaos is Governor Abbott. That’s where he continues to do political stunts in an inhumane way.”

The lawsuit, which names both the governor and the state of Texas as defendants, was filed by the Justice Department’s Environmental and Natural Resources Division in collaboration with the U.S. Attorney’s Office for the Western District of Texas.