Nothing in this section is intended or shall be construed to expand or alter existing statutory authorities in the Secretary so as to authorize the Secretary to enter into any agreement under subsection (b)(2) of this section and section
458ee
(c)(1) of this title with respect to functions that are inherently Federal or where the statute establishing the existing program does not authorize the type of participation sought by the tribe: Provided, however an Indian tribe or tribes need not be identified in the authorizing statute in order for a program or element of a program to be included in a compact under subsection (b)(2) of this section.