The program is authorized and empowered to obtain from any department or agency of the United States or from nongovernmental insurer any insurance or guaranty, or from a financial institution a letter of credit to the extent the insurance, guaranty, or letter of credit available now or in the future for the payment or repayment of, interest or principal in whole or in part, on any bonds issued by the program, or on any municipal securities purchased or held by the program, or on any guarantee issued by the program, pursuant to this chapter; and to enter into any agreement or contract with respect to any insurance or guaranty, or letter of credit, and pay any required fee, unless doing so would impair or interfere with the ability of the program to fulfill the terms of any agreement made with the holders of its bonds or guarantees.