No agreement or contract with an Indian tribe that encumbers Indian lands for a period of 7 or more years shall be valid unless that agreement or contract bears the approval of the Secretary of the Interior or a designee of the Secretary.
Subsection (b) shall not apply to any agreement or contract that the Secretary (or a designee of the Secretary) determines is not covered under that subsection.
Not later than 180 days after March 14, 2000, the Secretary shall issue regulations for identifying types of agreements or contracts that are not covered under subsection (b).