The shift in resources includes the deployment of around 200 employees who have volunteered from throughout the department, according to administration officials.
Additional federal employees have volunteered and the department is now going through the process of figuring out how to get them to the border, said an administration official.
Volunteers include personnel from the Transportation Security Administration, the Federal Emergency Management Agency and US Secret Service.
As part of the call for volunteers, the Secret Service has deployed non-law enforcement personnel to the border and the Federal Protective Service has deployed law enforcement personnel to the border to support CBP with "general law enforcement duties," according to the DHS official.
FEMA initially provided technical assistance and deployed teams to the border to assess and coordinate mass care and voluntary support requirements, according to a spokesperson for the agency.