Final answer:
The U.S. Treasury Department and government trust funds are the two main agencies that issue debt securities, such as Treasury Notes, Bonds, and Bills to finance government spending.
Step-by-step explanation:
The two government agencies that issue debt securities are the Treasury Department and government trust funds. The Treasury Department issues Treasury Notes (T-notes), Treasury Bonds (T-bonds), and Treasury Bills (T-bills) as a means to borrow money for periods longer than one year, with varying maturity dates and denominations. These securities are essential for raising funds to cover various public expenses, such as building roads or mass transit systems. An important element to consider when issuing these bonds is the confidence in the government's ability to repay its debt, which is high for the U.S. government, thereby allowing it to pay a relatively low interest rate. The debate over the U.S. debt ceiling often revolves around the balance between investing in the country's future and the concern about burdening future generations with excessive debt.