The head of the United States Federal Reserve has urged the US Congress to raise the country's borrowing limit.
Chairman Ben Bernanke said at the University of Michigan on Monday that small changes in interest rates will not make that much difference and that Congress should do its job.
The United States federal debt limit is $US16.4 trillion, which is expected to be reached in late February.
"Congress needs to be addressing these fiscal issues, and interest rates will eventually rise. We hope they'll rise because that means the economy will be strengthening," he said.
Mr Bernanke said the United States of America must not default on its debts.
"We're not going to be playing games with that. We are going to follow our mandate, which means do what's necessary to help the economy be strong," he reiterated.
"Congress should take care of their job, which is to address the fiscal issues which I talked about earlier, and I don't think that small changes in interest rates are really going to make that much difference."