The Adjutant General's Office said in a statement that the anticipated deployment involved the 155th Separate Armored Brigade based in Tupelo.
While most of the 155th's 49 units are in north and central Mississippi, it also has units in McComb and Monticello in the southern part of the state.
The 150th Engineer Battalion headquartered in Meridian with units in Quitman, Union and Carthage is part of that brigade.
Officials say the alert gives members of the 155th the chance to start planning and preparing for potential mobilization.
Guard spokesman Maj. Danny Blanton said he has no specifics about when that order will be issued or where troops will be headed. He said it's even possible the troops would not be mobilized.