(a) If a district enters into a contract with the United States, the district may deposit with the United States district bonds at 90 percent of par value to pay the amount owed by the district under the contract. The district shall pay interest on the bonds in the same manner that other bonds of the district are paid. Interest shall be paid regularly to the United States and applied in the manner provided in the contract.
(b) If bonds are not deposited as provided in Subsection (a) of this section, the board shall include in any levy or assessment made by the district an amount sufficient to make annual payments under the terms of the contract.