The deaths come as a dispute over immigration intensifies between Texas Governor Greg Abbott, a Republican, and the administration of U.S. President Joe Biden, a Democrat, as a record number of migrants have illegally crossed the border since Biden took office in 2021.
The migrants were attempting to cross the river near Shelby Park in Eagle Pass, according to officials, which is not a legal port of entry, and where the Texas National Guard this week added new concertina wire and fencing.
In a court filing in the U.S. Supreme Court on Friday, the U.S. government accused Texas of erecting the new barriers to block federal Border Patrol agents from reaching a boat ramp they use to access the Rio Grande.
In a response filed on Saturday, Texas said that federal Border Patrol agents had largely stopped using the boat ramp in recent months and, until Friday's filing, it was "unaware of federal law enforcement's current objections, and is working promptly to address them."
Federal Border Patrol agents learned at about 9 p.m. Central Time (0300 GMT Saturday) of a group of migrants in distress as they attempted to cross the Rio Grande, according to the statement by U.S. Representative Henry Cuellar, a Democrat.
Federal agents tried to contact Texas officials by telephone, but were unsuccessful, and then went in person to the Shelby Park entrance to speak to the Texas Military Department and the Texas National Guard officials there.
"However, Texas Military Department soldiers stated they would not grant access to the migrants - even in the event of an emergency - and that they would send a soldier to investigate the situation," Cuellar's statement said.
The Texas military officials "physically barred" U.S. border agents from entering the area and performing their roles of arresting people crossing the border illegally and providing humanitarian aid, Luis Miranda, a spokesperson for the U.S. Department of Homeland Security, said in a statement.
"The Texas governor's policies are cruel, dangerous, and inhumane, and Texas's blatant disregard for federal authority over immigration poses grave risks," Miranda's statement said. "The State of Texas should stop interfering with the U.S. Border Patrol's enforcement of U.S. law."
The bodies of the woman and two children were recovered on Saturday by Mexican authorities, Cuellar said. The identities of the three people have not been made public.
"This is a tragedy, and the State bears responsibility," Cuellar said.
A spokesperson for Texas's governor referred questions to the Texas Military Department, which did not respond to a request for comment.
Texas has increasingly sought to implement its own border controls, which have historically been the legal domain of the federal government.
(Reporting by Jonathan AllenEditing by Marguerita Choy and Christian Schmollinger)
By Jonathan Allen
