22 USC 1754 - Foreign currencies

(a) Availability and use 
Notwithstanding section 1306 of title 31, or any other provision of law, proceeds of sales made under section 1675p1 of this title, shall remain available and shall be used for any of the purposes of this chapter, giving particular regard to the following purposes
(1) for providing military assistance to nations or mutual defense organizations eligible to receive assistance under this chapter;
(2) for purchase of goods or services in friendly nations;
(3) for loans, under applicable provisions of this chapter, to increase production of goods or services, including strategic materials, needed in any nation with which an agreement was negotiated, or in other friendly nations, with the authority to use currencies received in repayment for the purposes stated in the section or for deposit to the general account of the Treasury of the United States;
(4) for developing new markets on a mutually beneficial basis;
(5) for grants-in-aid to increase production for domestic needs in friendly countries; and
(6) for purchasing materials for United States stockpiles.
(b) Availability to Members and employees of Congress; authorization requirements; reports 

(1) 
(A) Notwithstanding section 1306 of title 31, or any other provision of law
(i) local currencies owned by the United States which are in excess of the amounts reserved under section 2362 (a) of this title and of the requirements of the United States Government in payment of its obligations outside of the United States, as such requirements may be determined from time to time by the President; and
(ii) any other local currencies owned by the United States in amounts not to exceed the equivalent of $75 per day per person or the maximum per diem allowance established under the authority of subchapter I of chapter 57 of title 5 for employees of the United States Government while traveling in a foreign country, whichever is greater, exclusive of the actual cost of transportation;

shall be made available to Members and employees of the Congress for their local currency expenses when authorized as provided in subparagraph (B).

(B) The authorization required for purposes of subparagraph (A) may be provided
(i) by the Speaker of the House of Representatives in the case of a Member or employee of the House;
(ii) by the chairman of a standing or select committee of the House of Representatives in the case of a member or employee of that committee;
(iii) by the President of the Senate, the President pro tempore of the Senate, the Majority Leader of the Senate, or the Minority Leader of the Senate, in the case of a Member or employee of the Senate;
(iv) by the chairman of a standing, select, or special committee of the Senate in the case of a member or employee of that committee or of an employee of a member of that committee; and
(v) by the chairman of a joint committee of the Congress in the case of a member or employee of that committee.
(C) Whenever local currencies owned by the United States are not otherwise available for purposes of this subsection, the Secretary of the Treasury shall purchase such local currencies as may be necessary for such purposes, using any funds in the Treasury not otherwise appropriated.
(2) On a quarterly basis, the chairman of each committee of the House of Representatives or the Senate and of each joint committee of the Congress
(A)  shall prepare a consolidated report
(i)  which itemizes the amounts and dollar equivalent values of each foreign currency expended and the amounts of dollar expenditures from appropriated funds in connection with travel outside the United States, stating the purposes of the expenditures including per diem (lodging and meals), transportation, and other purposes, and
(ii)  which shows the total itemized expenditures, by such committee and by each member or employee of such committee (including in the case of a committee of the Senate, each employee of a member of the committee who received an authorization under paragraph (1) from the chairman of the committee); and
(B)  shall forward such consolidated report to the Clerk of the House of Representatives (if the committee is a committee of the House of Representatives or a joint committee whose funds are disbursed by the Chief Administrative Officer of the House) or to the Secretary of the Senate (if the committee is a committee of the Senate or a joint committee whose funds are disbursed by the Secretary of the Senate). Each such consolidated report shall be open to public inspection and shall be published in the Congressional Record within ten legislative days after the report is forwarded pursuant to this paragraph. In the case of the Select Committee on Intelligence of the Senate and the Permanent Select Committee on Intelligence of the House of Representatives, such consolidated report may, in the discretion of the chairman of the committee, omit such information as would identify the foreign countries in which members and employees of that committee traveled.
(3) 
(A) Each Member or employee who receives an authorization under paragraph (1) from the Speaker of the House of Representatives, the President of the Senate, the President pro tempore of the Senate, the Majority Leader of the Senate, or the Minority Leader of the Senate, shall within thirty days after the completion of the travel involved, submit a report setting forth the information specified in paragraph (2), to the extent applicable, to the Clerk of the House of Representatives (in the case of a Member of the House or an employee whose salary is disbursed by the Chief Administrative Officer of the House) or the Secretary of the Senate (in the case of a Member of the Senate or an employee whose salary is disbursed by the Secretary of the Senate). In the case of an authorization for a group of Members or employees, such reports shall be submitted for all Members of the group by its chairman, or if there is no designated chairman, by the ranking Member or if the group does not include a Member, by the senior employee in the group. Each report submitted pursuant to this subparagraph shall be open to public inspection.
(B) On a quarterly basis, the Clerk of the House of Representatives and the Secretary of the Senate shall each prepare a consolidation of the reports received by them under this paragraph with respect to expenditures during the preceding quarter by each Member and employee or by each group in the case of expenditures made on behalf of a group which are not allocable to individual members of the group. Each such consolidation shall be open to public inspection and shall be published in the Congressional Record within ten legislative days after its completion.
[1] See References in Text note below.