The Pentagon has ordered about 1,500 active-duty soldiers to be ready in case of a possible deployment to Minnesota, where federal authorities have been conducting a massive immigration enforcement operation, two defense officials said Sunday.

The officials, who spoke on condition of anonymity to discuss sensitive military plans, said two infantry battalions of the Army's 11th Airborne Division have been given prepare-to-deploy orders. The unit is based in Alaska and specializes in operating in arctic conditions.