The head of the U.S. central bank has warned that the country's economic recovery still needs help to overcome key obstacles, including a high unemployment rate.

Federal Reserve Chairman Ben Bernanke told the House Financial Services Committee Wednesday that efforts to spark the economy have helped increase demand for products and consumer spending.  But he said economic growth could be hurt by the weak job market, especially because millions of Americans have been out of work for six months or more.

Bernanke also said the central bank will continue to keep its benchmark interest rate at "exceptionally low levels" for an extended period.

The Federal Reserve cut the lending rate to an all-time low of zero to one-quarter of a percent in order to help stimulate lending and spark the economy.

Last week, the Federal Reserve predicted the U.S. unemployment rate will average between 9.5 and 9.7 percent this year.

Some lawmakers have been concerned that the country's massive $787 billion economic stimulus package has done little to help the economy, while driving up the country's debt.

Bernanke agreed that government spending will have to be reduced in coming years, but he said most experts believe the stimulus package has prevented the U.S. economy from getting worse.

He also said the U.S. economy likely will grow about 3.5 percent this year and as much as 4 percent in 2011.

U.S. Treasury Secretary Timothy Geithner also testified before Congress Wednesday.

Geithner told lawmakers the country must reduce its growing debt, but he said government spending still is needed to make sure the economy does not slip back into recession.

He also said the economy faces dangers from rising problems in the housing sector.  Recent reports have estimated that as many as three million Americans could lose their homes this year because they cannot afford to pay their mortgages.

A Commerce Department report Wednesday also showed potential problems in the housing industry.  It said sales of new homes have fallen to a record low, dipping 11 percent in January.  

The collapse of the U.S. housing market played a role in sparking the global financial crisis, and improvements in the housing sector are seen as important for a sustainable economic recovery.

Some information for this report was provided by AP, Bloomberg and Reuters.