WASHINGTON, Sept. 8 (Xinhua) -- U.S. Federal Reserve Chairman Ben Bernanke said Thursday the American economy is weaker than expected and the central bank would take all efforts to create more jobs and avoid the world's largest economy from falling into another recession.

"It is clear that the recovery from the crisis has been much less robust than we had hoped," Bernanke said in a speech delivered during a forum in Minneapolis, Minnesota. "The Federal Reserve will certainly do all that it can to help restore high rates of growth and employment in a context of price stability."

The central bank chief said that "sluggish" was particularly evident in the first half of this year, with real gross domestic product estimated to have increased at an annual rate of less than 1 percent, on average, in the first and second quarters.

The household spending is "unusually" weak, and housing market remains in trouble, noted the Fed chief.

He said that the Federal Open Market Committee, the central bank's policy making body, now expects a somewhat slower pace of recovery over coming quarters than it did earlier summer, with greater downside risks to the economic outlook.

Still, Bernanke expressed optimistic attitude toward U.S. economy's long-term prospect.

Bernanke said that as monetary and fiscal policymakers consider the appropriate policies to address the economy's current weaknesses, it is important to acknowledge the U.S. economy's enduring strengths.