WASHINGTON — The chairman of the Federal Reserve, Ben S. Bernanke, vowed on Wednesday to do whatever it took to pull the economy out of its downward spiral, even as he acknowledged that the most recent indicators were “dismal.”

Speaking at the National Press Club, the first time that a Fed chairman has taken questions from journalists in a public forum, Mr. Bernanke defended the central bank’s efforts and tried to allay concerns that it had been printing money at a dangerous pace.

“The Federal Reserve has done, and will continue to do, everything possible within the limits of its authority to assist in restoring our nation to financial stability,” he said.

Mr. Bernanke made it clear that he supported a stimulus package of increased spending and tax cuts, though he declined to comment on the particulars of the measure signed on Tuesday by President Obama or on Mr. Obama’s plan to reduce the rising tide of home foreclosures.

He also warned that the unemployment rate, which reached 7.6 percent last month, would climb to 8 percent “for sure.” Indeed, the central bank released a separate report soon afterward showing that Fed policy makers had become considerably more pessimistic about the economy’s prospects for this year.

The “central tendency” of forecasts by the presidents of the Federal Reserve’s district banks and of governors on the Federal Reserve Board showed that they expected unemployment to reach 8.5 to 8.8 percent in 2009. Last October, policy makers expected unemployment to top out at 7.1 to 7.6 percent.

Fed policy makers also expect the economy to shrink this year in a range of 0.5 to 1.3 percent, which mainly reflects deepening gloom about the severity of the downturn in the first half of this year. Last October, most Fed officials had predicted that the United States would come out of the recession quickly enough to end this year with a small gain.

Bleak economic data reflecting a sharpening slide in housing, trade, industrial production, spending and employment rates “more than offset” any potential impact from a stimulus plan, the Fed said in the report, which reflected the minutes of its Jan. 27-28 meeting.

“Financial markets continued to be strained over all, credit remained unusually tight for both households and businesses, and equity prices had fallen further,” the report said.

For the first time, the Fed also released projections of longer-term growth going beyond its normal one-to-three-year predictions. The committee members said that the American economy was expected to grow by 2.5 to 2.7 percent annually over the next five to six years, and that unemployment rates would hover near 5 percent in the longer term.

Mr. Bernanke focused his remarks on the Fed’s expansion of lending activities since last fall. Using its power to create additional money at will, the central bank has more than doubled its “balance sheet” of holdings to about $2 trillion, from $900 billion since last September. The expansion reflects the Fed’s effort to thaw the frozen credit markets by pouring money into the financial system through a half-dozen new programs.

Acknowledging that some experts had raised fears that the Fed would end up stoking inflation, or losing money on risky loans, Mr. Bernanke argued that the central bank would be able to reverse course fairly swiftly as soon as the crisis abated.

“A significant shrinking of the balance sheet can be accomplished relatively quickly,” he said, adding that most of the Fed’s new holdings were short-term loans that had to be repaid within a few months. Most of the loans, he added, entail very little credit risk because they are either routine, short-term loans to financial institutions or currency “swap agreements” with foreign central banks.

“For the great bulk of Fed lending, the credit risks are extremely low,” Mr. Bernanke said. About 5 percent of the Fed’s lending entails comparatively risky assets, and those are the ones involved in the central bank’s rescues of Bear Stearns and the American International Group.

Mr. Bernanke acknowledged growing concerns about the lack of openness about who is receiving loans from the Fed and exactly what kind of collateral it is holding. He said the Fed had begun a “thorough review” of its disclosure policies, which is being carried out by a committee headed by Donald L. Kohn, the central bank’s vice chairman.

“Extraordinary times call for extraordinary measures,” Mr. Bernanke said. “Increased transparency is the best way to demonstrate that the Federal Reserve’s nontraditional policies are well conceived.”

Though the Fed chairman occasionally became embroiled in the technical intricacies of the central bank’s efforts, he seemed comfortable fielding questions — and deft at avoiding ones he did not want to answer.

Asked at the end of the session whether he thought the Yankees star Alex Rodriguez should be allowed into the National Baseball Hall of Fame after admitting that he had used steroids, Mr. Bernanke stepped up to the lectern, smiled and said, “I like baseball.”