Total U.S. federal debt has exceeded $US40 trillion, while annualised interest costs have climbed to $US1.25 trillion. Since late February, U.S. government borrowing rates have jumped by more than 20%. The budget deficit this fiscal year is projected at about $US2 trillion, around 6% of GDP. Analysts warn that the mix of higher rates, an AI investment boom, inflation and Trump administration policies is pushing the global economy toward a tipping point.