SACRAMENTO, Calif. (AP) — California Gov. Jerry Brown agreed Wednesday to deploy 400 National Guard troops at President Donald Trump’s request, but not all will head to the U.S.-Mexico border as Trump wants and none will enforce federal immigration enforcement.

“Let’s be clear on the scope of this mission,” the Democrat Brown wrote in a letter to the Trump administration. “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.”

Instead, Brown said the troops would join an existing program to combat transnational drug crime, firearms smuggling and human trafficking. They would join 250 existing California National Guard troops, including 55 who are at the border.

Trump wants up to 4,000 troops sent to the border to combat illegal immigration and drug trafficking and has already won commitments for about 1,600 from the Republican governors of the other states that border Mexico — Arizona, New Mexico and Texas.

The California Guard members may be deployed at the border, the coast and elsewhere statewide, Brown said.

The federal government must agree to the terms before the troops would be deployed.

California deployed troops to the border under former Presidents George W. Bush in 2006 and Barack Obama in 2010.