The federal government's deficit nearly tripled in the first nine months of the fiscal year, a surge that's bound to raise concerns about the country's rising debt levels.

The Treasury Department said Thursday that the budget gap from October through June was nearly $1.4 trillion — a 170% increase from the same period a year earlier. The federal government operates under a fiscal year that begins October 1.

The shortfall adds to an already large federal debt — estimated at more than $32 trillion. Financing that debt is increasingly expensive as a result of rising interest rates. Interest payments over the last nine months reached $652 billion — 25% more than during a same period a year ago.