In the event of any losses, as determined by the Board of Directors of the Bank, incurred on loans, guarantees, and insurance extended under this subchapter, the first $100,000,000 of such losses shall be borne by the Bank; the second $100,000,000 of such losses shall be borne by the Secretary of the Treasury; and any losses in excess thereof shall be borne by the Bank. Reimbursement of the Bank by the Secretary of the Treasury of the amount of losses which are to be borne by the Secretary of the Treasury as aforesaid shall be from funds made available pursuant to section 635 of this title. All guarantees and insurance issued by the Bank shall be considered contingent obligations backed by the full faith and credit of the Government of the United States of America.l