JACKSON HOLE, Wyo. — The Federal Reserve chairman, Ben S. Bernanke, delivered on Friday a detailed and forceful argument for new steps to stimulate the economy, reinforcing earlier indications that the Fed is on the verge of action.

Mr. Bernanke said that the Fed’s policies over the last several years have provided significant benefits, but that a clear need remained for the Fed to do more and that, in his judgment, the likely benefits of such actions outweighed the potential costs.

“It is important to achieve further progress, particularly in the labor market,” Mr. Bernanke said in his prepared remarks. “Taking due account of the uncertainties and limits of its policy tools, the Federal Reserve will provide additional policy accommodation as needed to promote a stronger economic recovery and sustained improvement in labor market conditions in a context of price stability.”