WASHINGTON, US - PRESIDENT Barack Obama said on Sunday the US financial system could still implode if a large bank were to fail, and 'big problems' could result if the government does not try to lessen the risk.

'I think that systemic risks are still out there,' Mr Obama said in an interview on the CBS programme '60 Minutes.' 'If we did nothing you could still have some big problems.

There are certain institutions that are so big that if they fail, they bring a lot of other financial institutions down with them.' Mr Obama said when he took office that he had not expected to see such a sharp economic decline, particularly in job losses.

'I mean if you look at just ... hundreds of thousands, now millions of jobs being shed over the course of two months, or three months - that slope is a lot steeper than anything we've ...seen before,' he said.

But he added there was a 'potential silver lining' - that the recovery might be equally as fast as the downturn.

Asked when he thought the economic crisis might end, Mr Obama said there were already 'flickers of hope' with low interest rates and an increasing number of mortgage refinancings.

'That promises the possibility at least of the housing market bottoming out and stabilising,' he said. 'It's not going to happen equally in every part of the country.

Mr Obama said there was a limit to the amount of money that the US government could spend or print to help improve the economy.

'The limit is our ability to finance these expenditures through borrowing,' he said. 'The dollar is still strong because people are still buying Treasury Bills. They still think that's the safest investment out there.' 'If we don't get a handle on this, and also start looking at our long-term deficit projections, at a certain point people will stop buying those Treasury Bills.' -- REUTERS