22 U.S.C. § 287d: Noncombatant assistance to United Nations

the detail to the United Nations, under such terms and conditions as the President shall determine, of personnel of the armed forces of the United States to serve as observers, guards, or in any non-combatant capacity, but in no event shall more than a total of one thousand of such personnel be so detailed at any one time: Provided , That while so detailed, such personnel shall be considered for all purposes as acting in the line of duty, including the receipt of pay and allowances as personnel of the armed forces of the United States, credit for longevity and retirement, and all other perquisites appertaining to such duty: Provided further , That upon authorization or approval by the President, such personnel may accept directly from the United Nations (a) any or all of the allowances or perquisites to which they are entitled under the first proviso hereof, and (b) extraordinary expenses and perquisites incident to such detail; the furnishing of facilities, services, or other assistance and the loan of the agreed fair share of the United States of any supplies and equipment to the United Nations by the Department of Defense, under such terms and conditions as the President shall determine; the obligation, insofar as necessary to carry out the purposes of clauses (1) and (2) of this subsection, of any funds appropriated to the Department of Defense or any department therein, the procurement of such personnel, supplies, equipment, facilities, services, or other assistance as may be made available in accordance with the request of the United Nations, and the replacement of such items, when necessary, where they are furnished from stocks. Whenever personnel or assistance is made available pursuant to the authority contained in subsection (a)(1) and (2) of this section, the President shall require reimbursement from the United Nations for the expense thereby incurred by the United States: Provided , That in exceptional circumstances, or when the President finds it to be in the national interest, he may waive, in whole or in part, the requirement of such reimbursement: Provided further , That when any such reimbursement is made, it shall be credited, at the option of the appropriate department of the Department of Defense, either to the appropriation, fund, or account utilized in incurring the obligation, or to an appropriate appropriation, fund, or account currently available for the purposes for which expenditures were made. In addition to the authorization of appropriations to the Department of State contained in section 287e of this title , there is hereby authorized to be appropriated to the Department of Defense, or any department therein, such sums as may be necessary to reimburse such departments in the event that reimbursement from the United Nations is waived in whole or in part pursuant to authority contained in subsection (b) of this section. Nothing in this subchapter shall authorize the disclosure of any information or knowledge in any case in which such disclosure is prohibited by any other law of the United States.