The Secretary shall establish and maintain a program to attract Indian and Alaska Native professional foresters and forester technicians who have already graduated from their course of postsecondary or graduate education for employment in either the Bureau of Indian Affairs forestry programs or, subject to the approval of the tribe, in tribal forestry programs. According to such regulations as the Secretary may prescribe, such program shall provide for the employment of Indian and Alaska Native professional foresters or forestry technicians in exchange for the Secretary’s assumption of the employee’s outstanding student loans. The period of employment shall be determined by the amount of the loan that is assumed.