Updated at 8:55 p.m.

California will join Texas, Arizona, and New Mexico in sending National Guard troops to help secure the U.S.-Mexico border, Gov. Jerry Brown announced Wednesday afternoon.

In a letter to Defense Secretary Jim Mattis and Homeland Security Secretary Kirstjen Nielsen, the Democratic governor said he will accept federal funding and in turn deploy 400 guardsmen to help with border and immigration efforts both at the border and in the interior of the state.

"Your funding for new staffing will allow the Guard to do what it does best: support operations targeting transnational criminal gangs, human traffickers, and illegal firearm and drug smugglers along the border, the coast and throughout the state," Brown said in a statement.

"Combating these criminal threats are priorities for all Americans — Republicans and Democrats," he added, noting that California assisted previous presidents, George W. Bush and Barack Obama, in similar situations.

"But let's be crystal clear on the scope of this mission. This will not be a mission to build a new wall. It will not be a mission to round up women and children or detain people escaping violence and seeking a better life. And the California National Guard will not be enforcing federal laws," he stressed.





A senior Border Patrol agent said Monday that National Guard troops were not being sent to the U.S.-Mexico border to make arrests of illegal entrants, but to take on some of the day-to-day and long-term tasks that agents have had to carry out instead of focusing on their patrolling duties.

"They have capabilities to provide for us that can make it much easier for us to secure the border — things like air support, repairing, creating infrastructure to assist us, logistical support, assisting with surveillance capabilities," El Paso Sector Chief Patrol Agent Aaron E. Hull told reporters during a press conference in Santa Teresa, N.M., Monday. "They're going to be providing administration support, not providing any law enforcement assistance. We provide all the law enforcement response."

About 500 National Guard troops went to the U.S.-Mexico border late Friday, the Department of Defense and Homeland Security announced last week.

Republican Govs. Greg Abbott of Texas, Doug Ducey of Arizona, and Susana Martinez of New Mexico have pledged a total of 1,600 troops to help CBP respond to last month's major uptick in illegal immigrant apprehensions.

Brown had been the only border-state governor not to support the operation despite talks with DHS and DOD, until now.

"The secretary recently spoke with Governor Brown. She is pleased to have the support of all four border governors to help secure our southwest border," a DHS spokesperson said in a statement. "Issues of border security require the partnership of the federal government and our state and local allies to be successful.”

The administration could send thousands of troops to help CBP and Border Patrol. Mattis approved a plan for 4,000 guardsmen and airmen earlier Friday.

Trump has said he envisions 2,000 to 4,000 service members being deployed.

During illegal immigrant apprehension spikes under the Bush and Obama administrations, both presidents ordered 6,000 guardsmen and 1,200 guardsmen to the border, respectively.