The Democratic governor broke a week of silence Wednesday by agreeing to contribute 400 troops, though not all will be on the border. The main objective is to provide support for the Department of Homeland Security's mission to secure the U.S. -Mexico border, with a mission end-date of September 30.
Gov. Abbott reminded the troops of their mission: to assist the Border Patrol by being their eyes and ears at the border. "Thank you Jerry, good move for the safety of our Country!"
"This will not be a mission to build a new wall", Brown wrote.
Federal law, notably the Posse Comitatus Act of 1878, sharply limits military involvement in civilian law enforcement, creating a supporting role for the Guard. "There has been an increase of more than 200 percent of people coming across the border without authority".
California's deployment will happen pending review and approval by the federal government.
"Importantly, they relieved agents of more administrative tasks so they could return to patrol and enforcement duties".
Governor Abbott says he has received calls from governors of other states who want to offer their National Guard members to take part in the operation.
Reaction in California was limited, with few of Brown's allies or opponents weighing in.
Pro-immigrant organizations on the border said the governor has the wrong focus.
On Wednesday, Sessions was in Las Cruces, New Mexico, where he spoke at an annual meeting of the Texas Border Sheriff's Coalition.
It's the latest group of soldiers preparing for a surveillance and reporting mission along the banks of the Rio Grande where there's already 762 of them watching for any smuggling activity from the other side.
Governor Greg Abbott made a stop at the Texas-Mexico border on Thursday afternoon.
"We don't know yet what the total cost of his financial operation will be", General Joseph L. Lengyel, of the National Guard Bureau, said.
With that help, agents will "get back into doing law enforcement work", Karisch said.
Brown said California's troops would join an existing program to combat transnational drug crime, firearms smuggling and human trafficking.
Last week, officials with the Texas Military Department confirmed the troops' deployment to the Valley, clarifying they would serve in a support role for Border Patrol and Customs and Border Protection officials. Although New Mexico Gov. Susana Martinez has - as the Santa Fe New Mexican reports - "been critical in the past of the president's approach to border security and immigration", her office said the state is deploying 80 National Guard troops this week and expects to eventually deploy 250. California had accepted similar requests by President George W. Bush in 2006 and President Barack Obama in 2010, as Brown noted in his letter.