Several agencies are taking part in the search.
CNN  — 

A Texas Army National Guard soldier who was participating in a mission along the border with Mexico is missing, according to the state’s military department.

Maverick County Sheriff Tom Schmerber said earlier a Texas National Guard member tried to rescue a female who was crossing the Rio Grande in the area of Eagle Pass, Texas, and he “never came up.”

The female made it to the US side of the border and was taken into custody by federal authorities. The identity of the guard member has not been released, Schmerber said.

The Texas Department of Public Safety and Border Patrol are helping in the search, according to a statement from the Texas Military Department.

The soldier was assigned to Operation Lone Star, Gov. Greg Abbott’s effort to combat what he says is a crisis at the US-Mexico border.

The governor said his office is working “with the Texas National Guard and other law enforcement agencies as they search for the missing soldier in Eagle Pass. Updates will be provided as additional details become available.”

Abbott, who is up for reelection, launched Operation Lone Star last March. The operation – which leaned on resources from the state’s public safety department and Texas National Guard – has swelled to more than 10,000 service members.

The National Guard role in Operation Lone Star is often supporting law enforcement. Members of the military are barred from carrying out law enforcement activities, such as arrests or searches, without prior authorization.

CNN’s Priscilla Alvarez contributed to this story.