Section 105. There shall be a department of veterans’ services under the supervision and control of a secretary of veterans’ services, who shall be a veteran appointed by the governor, and who shall serve at the pleasure of the governor and may be removed by governor at any time. This position shall be classified in accordance with section 45 of chapter 30 and the salary shall be determined in accordance with section 46C of said chapter 30. The secretary shall devote their full-time during business hours to the duties of their office. The secretary shall be the state agent for the settlement of pension, bounty, back pay, compensation and other claims of citizens of the commonwealth against the government of the United States, or any state thereof, on account of military or naval service and shall assist and advise war veterans, and their dependents, heirs or legal representatives, with respect to the filing, prosecution and settlement of such claims.