(a) Notwithstanding any other law, the head of a Federal agency shall not approve any program or project or any grant to, or contract or agreement with, an acquiring agency under which Federal financial assistance will be available to pay all or part of the cost of any program or project which will result in the acquisition of real property on and after January 2, 1971, unless he receives satisfactory assurances from such acquiring agency that—
in acquiring real property it will be guided, to the greatest extent practicable under State law, by the land acquisition policies in section 4651 of this title and the provisions of section 4652 of this title, and
(b) For purposes of this section, the term “acquiring agency” means—
a State agency (as defined in section 4601(3) of this title) which has the authority to acquire property by eminent domain under State law, and
a State agency or person which does not have such authority, to the extent provided by the head of the lead agency by regulation.
(Pub. L. 91–646, title III, § 305, Jan. 2, 1971, 84 Stat. 1906; Pub. L. 100–17, title IV, § 417, Apr. 2, 1987, 101 Stat. 256.)