Migrants trying to enter the US from Mexico approach the site where workers are assembling large buoys to be used as a border barrier along the banks of the Rio Grande, in Texas, on July 11, 2023. (AP)

The US Justice Department threatened to prosecute Texas for anti-migrant buoys placed in the Rio Grande River along the border with Mexico, but Texas Governor Greg Abbott retaliated on Monday.

Late last week, the Department informed the state that the huge orange buoys at Eagle Pass, Texas, were obstructing river movement without authorization from the federal government.

"This floating barrier poses a risk to navigation, as well as public safety, in the Rio Grande River, and it presents humanitarian concerns," the Department said.

Abbott claimed that he had the authority to place the buoys in order to defend the "sovereign" interests of Texas in a response letter sent to President Joe Biden on Monday.

He charged Biden with failing to carry out his own obligations to close the southern border with Mexico and stop the flow of migrants.

"If you truly care about human life, you must begin enforcing federal immigration laws," Abbott wrote.

"By doing so, you can help me stop migrants from wagering their lives in the waters of the Rio Grande River," he said, adding that "Texas will see you in court, Mr President."

This month, massive razor wire obstacles on the shore and a string of buoys were placed in the river at a well-known migrant crossing spot.

There have been tales of migrants needing rescue after being entangled in the razor wire.

Additionally, according to a US Customs and Border Protection letter that was leaked, the razor wire installed by state officers hampered the agency's own border enforcement efforts.

Prior to the Justice Department's deadline of 2:00 pm Eastern time (1800 GMT) for Texas to begin negotiations or face a federal lawsuit, Abbott made his letter public.