For the purpose of keeping to a minimum the cost to the United States of participation in the Association, the Secretary of the Treasury is authorized and directed to issue special notes of the United States from time to time, at par, and to deliver such notes to the Association in exchange for dollars to the extent permitted by the articles. The special notes provided for in this subsection shall be issued under the authority and subject to the provisions of chapter
31 of title
31, and the purposes for which securities may be issued under that chapter are extended to include the purposes for which special notes are authorized and directed to be issued under this subsection, but such notes shall bear no interest, shall be nonnegotiable, and shall be payable on demand of the Association. The face amount of special notes issued to the Association under the authority of this subsection and outstanding at any one time shall not exceed, in the aggregate, the amount actually paid to the Association under the articles.