“Governments aren’t like people,” he wrote. “[They] must service their debts — pay interest and repay principal when bonds come due — but they don’t necessarily have to pay them off; they can issue new bonds to pay principal on old bonds, and even borrow to pay interest as long as overall debt doesn’t rise too much faster than revenue.”
https://finance.yahoo.com/news/us-national-debt-sits-33-123000638.html