The U.S. government has issued 30-year Treasury bonds at the highest borrowing costs since 2001.

This is attributed to concerns over persistently surging national debt and still-high inflation.

In the $25 billion 30-year Treasury auction held by the U.S. Department of the Treasury on the 13th (local time), the yield was set at 5.22%.

This marks the highest level since 2001.

The yield for this issuance is significantly higher than the previous month's 5.06%.

Compared to January 2025 (4.91%), just before President Donald Trump took office, it has jumped by a substantial 0.3 percentage points.

The bid-to-cover ratio was 2.39 times, which is higher than the average of the previous six auctions.

A day earlier, the yield on the $42 billion 10-year Treasury issuance was 4.69%, the highest since 2007.

The rise in long-term bond yields is interpreted as stemming from underlying concerns over the national debt alongside inflation worries.

Gennadiy Goldberg, head of U.S. rates strategy at TD Securities, interpreted, "While demand for long-term bonds still exists, it shows that investors are demanding higher yields."

U.S. national debt has surged to $40 trillion, pushing the national debt-to-GDP ratio past 100% to 100.2% as of the end of the first quarter.

Except for a temporary spike during the pandemic in the second quarter of 2020, this is the first time the ratio has exceeded 100% since right after World War II.

The Congressional Budget Office (CBO) under the U.S. Congress expects the debt-to-GDP ratio to surpass 106% by 2030, which would be the highest since World War II.

In addition, soaring prices driven by the war with Iran have increased the burden on investors.

Goldberg said, "Ultimately, this becomes a problem for the Treasury because the Treasury must finance government operations at higher interest rates."

U.S. national debt and borrowing costs have nearly doubled over the past decade due to massive spending during the pandemic.

Furthermore, concerns that soaring energy prices resulting from the war with Iran will make it difficult for the Federal Reserve to control inflation hovering above 3% also played a role.

(Photo: AP, Yonhap News)