First of all, the interest rate formation mechanism in the United States is basically formed by the market, which is what we have long said about interest rate marketization, and the US central bank, the Federal Reserve, usually only controls short-term interest rates. How does the Fed control interest rates? It is achieved by buying and selling government bonds of various maturities in the open market. For example, in the current situation, the Federal Reserve wants to lower interest rates, so it buys a large amount of US Treasury bonds (of various maturities, including long-term and short-term) in the open market, and the demand for treasury bonds is in short supply, so the price goes up, and the yield (that is, interest rate) goes down when the price goes up. The market interest rate in the United States, or the national debt interest rate, is basically formed in this way.

Then let's talk about the relationship between the bank's loan interest rate and the interest rate of US Treasury bonds. Treasury bonds are usually risk-free, or the risk is extremely low. When banks lend, they will refer to the interest rate of treasury bonds and add some interest (margin). For example, the 1-year interest rate of US Treasury bonds is about 2.25% now, so when banks lend 1-year loans, considering the risk of repayment, they will add a percentage to it. For example, for loans to large companies, the possible loan interest rate is 3.25%. Therefore, the long-term loan interest rate is based on the yield of US Treasury bonds.

at this point, I think your question has been answered: when the long-term yield of government bonds decreases, the long-term loan interest rate of banks also decreases.