Federal Reserve chair Ben Bernanke says the U.S. jobs market remains 'quite weak.' (Lawrence Jackson/Associated Press)

Federal Reserve chair Ben Bernanke said record low interest rates are still needed to foster U.S. economic growth as the country recovers from its worst battering since the Great Depression of the 1930s.

In making his semi-annual monetary policy report to the U.S. Congress, Bernanke said short-term rates will remain low for some time yet.

The Fed "continues to anticipate that economic conditions … are likely to warrant exceptionally low levels of the federal funds rate for an extended period," he said.

"Although the federal funds rate is likely to remain exceptionally low for an extended period, as the expansion matures, the Federal Reserve will at some point need to begin to tighten monetary conditions to prevent the development of inflationary pressures."

The prepared text Bernanke read offered no new hints about when the Fed would tighten money supply by increasing its key overnight rate, but most observers say that's not likely to happen for many months.

The target range for the federal funds rate has been zero to 0.25 per cent since December 2008.

Bernanke warned that economic recovery would remain sluggish and said the "job market remains quite weak." Bernanke noted that more than 40 per cent of the unemployed have been out of work for more than six months. That's almost twice the rate of a year ago. The U.S. unemployment rate was 9.7 per cent in January.

Last week, the Fed raised the rate U.S. banks pay for emergency loans — the discount rate — by a quarter of a percentage point. Bernanke said that should not be interpreted as a sign that tighter credit for consumers and businesses is imminent.

"Getting people back to work — socially, most of all, but also for the overall economy — is critical," said committee chairman Barney Frank, a Democrat from Massachusetts.

Voters are reeling from record home foreclosures and major job losses and many small businesses are still saying it's tough to get a loan. At the same time, bailed-out Wall Street banks, which the Fed supervises, are again reporting profits.