Any town, city, or county official, so designated in a written agreement between the commissioner of the department of health and human services and the selectmen of a town, the city council of a city or the county commissioners of a county, may receive, store, issue and sell food stamps under the food stamp program established under N.H. Rev. Stat. § 161:2, XIII, as agent of the commissioner in the respective town, city or county, in accordance with and pursuant to the terms of said written agreement. Said designated official shall be bonded and insured as such agent in the manner and amount required by the commissioner, and the commissioner shall pay the cost thereof from funds appropriated for the administration of the food stamp program.