A tribal government participating in a demonstration program under this chapter is authorized to utilize funds available under such plan to place participants in training positions with private employers and pay such participants a training allowance or wage for a period not to exceed 12 months, if the tribal government obtains a written agreement from the private employer to provide on-the-job training to such participants and, upon satisfactory completion of the training period, to guarantee permanent employment to such participants for a minimum of 12 months.