DOJ warns Texas against using buoys in Rio Grande to stop migrants

The Justice Department on Friday warned Texas GOP Gov. Greg Abbott that his administration's use of ballards -- or buoys -- in the Rio Grande to stop migrants could bring legal action.

"The State of Texas's actions violate federal law, raise humanitarian concerns, present serious risks to public safety and the environment, and may interfere with the federal government's ability to carry out its official duties," the letter obtained by ABC News says.

Earlier this week, Abbott had ballards installed in the river in an effort to deter migrants from crossing.

"Texas's unauthorized construction of the floating barrier is a prima facie violation of the Rivers and Harbors Act. This floating barrier poses a risk to navigation, as well as public safety, in the Rio Grande River, and it presents humanitarian concerns," the letter says. "Thus, we intend to seek appropriate legal remedies, which may include seeking injunctive relief requiring the removal of obstructions or other structures in the Rio Grande River."

Abbott responded, "Texas has the sovereign authority to defend our border, under the U.S. Constitution and the Texas Constitution. We have sent the Biden Administration numerous letters detailing our authority, including the one I hand-delivered to President Biden earlier this year."

Abbott's office unveiled a page on his website dedicated to touting Operation Lone Star's efforts to combat the "humanitarian crisis" he blames on President Joe Biden.

Abbott's press release page, dated Friday, says his administration, with Texas' Department of Public Safety and the Texas National Guard, are "continuing to work together to secure the border; stop the smuggling of drugs, weapons, and people into Texas; and prevent, detect, and interdict transnational criminal behavior between ports of entry," citing statistics on the hundreds of thousands of apprehensions and criminal arrests the operation has achieved.

"Operation Lone Star continues to fill the dangerous gaps created by the Biden Administration's refusal to secure the border. Every individual who is apprehended or arrested and every ounce of drugs seized would have otherwise made their way into communities across Texas and the nation due to President Joe Biden's open border policies," the page says.

Abbott has continued his response to DOJ's expressed intension to file legal action over the floating barriers on social media: "We will see you in court," Abbott tweeted.

-ABC News' Sasha Pezenik contributed to this report.