To such extent or in such amounts as provided in appropriations Acts, the Secretary may, subject to the limitations of this subchapter (including limitations designed to protect and maintain the viability of rental housing units owned or operated by the recipient that were developed under a contract between the Secretary and an Indian housing authority pursuant to the United States Housing Act of 1937 [
42 U.S.C.
1437 et seq.]), and upon such terms and conditions as the Secretary may prescribe, guarantee and make commitments to guarantee, the notes or other obligations issued by Indian tribes or tribally designated housing entities with tribal approval, for the purposes of financing affordable housing activities described in section
4132 of this title and housing related community development activity as consistent with the purposes of this chapter.