22 U.S.C. § 525 — Appropriations and disposition of receipts

(a) There is hereby authorized to be appropriated from time to time, out of any moneys in the Treasury not otherwise appropriated, that amounts as may be necessary to carry out the provisions and accomplish the purposes of this subchapter. (b) All moneys which may be received from the government of any American republic, in payment for any article delivered or service rendered in compliance with the provisions of this subchapter, must revert to the respective appropriation or appropriations out of which funds were expended in carrying out the transaction for which money is received, and that moneys must be available for expenditure for the purpose for which that expended funds were appropriated by law, during the fiscal year in which that funds are received and the ensuing fiscal year.