WASHINGTON - The Federal Reserve chairman, Ben S. Bernanke, on Wednesday dismissed proposals to escalate the Fed's economic stimulus campaign as "reckless," arguing that the costs would be high and the benefits uncertain. Ben S. Bernanke, chairman of the Federal Reserve, discussed the country's economic growth during a news conference on Wednesday. Mr. Bernanke spoke after the Fed's policy-making committee ended a two-day meeting with a statement affirming its intention to continue until late 2014, and possibly longer, policies that aim to increase spending by holding down interest rates, rewarding borrowers and punishing savers. The committee again demurred, however, from expanding those efforts, despite its prediction that millions of Americans would not find jobs for years to come. The Fed also released a set of economic forecasts by 17 senior officials, only some of whom vote on monetary policy, showing that their expectations for domestic economic growth for this year have increased modestly since January. These documents showed that a majority of the 10 officials who vote on policy now foresaw the Fed raising interest rates by the end of 2014. Taken together, the documents suggested that Mr. Bernanke, who effectively has control over monetary policy, may be facing increased pressure from Fed officials concerned that the central bank has promised too much, even as he confronts mounting external criticism from those who say he is not doing enough. Nine of the 10 members of the committee supported the public declaration that the Fed planned to continue these policies at least through late 2014. Jeffrey M. Lacker, president of the Federal Reserve Bank of Richmond, dissented, saying rates would need to rise sooner. It said that unemployment would "decline gradually" and that inflation remained under control despite the impact of the recent rise in oil prices, which it regarded as temporary. At a news conference Wednesday afternoon, Mr. Bernanke offered his most complete public explanation to date for the calibration of the Fed's policies. The Fed is charged by Congress with minimizing unemployment and maintaining stable prices. The Fed predicts that unemployment will remain high for years to come, and it predicts that inflation will remain under control. Under those circumstances, he was asked, why not take stronger action to reduce unemployment? Mr. Bernanke said that he was concerned about the high level of unemployment but that the Fed's ability to encourage job creation was constrained by its responsibility to keep inflation low and stable. Lowering the cost of borrowing to spur job creation tends to increase inflation. The current pace is already close to the 2 percent level the Fed considers ideal for long-term economic growth. Mr. Bernanke said it would be irresponsible for the Fed to pursue a temporary increase in the rate of inflation because it would surrender the credibility of its longstanding commitment to keep inflation around 2 percent. Moreover, he said, the impact on job growth would be "quite tentative and perhaps doubtful." "The question is, "Does it make sense to actively seek a higher inflation rate in order to achieve a slightly increased pace of reduction in the unemployment rate?" " he asked. The view of the committee is that that would be very reckless. The Fed also could expand its purchases of Treasury bonds and mortgage-backed securities, which it views as a way to reduce borrowing costs without the same risk of increased inflation. Mr. Bernanke said this remained under discussion, but he added that he regarded the current level of Fed policy as an appropriate response to existing and projected economic conditions. The Federal Open Market Committee "does not appear inclined to take any further aggressive steps, as the labor market recovery has picked up since the fall of 2011," Stuart G. Hoffman, chief economist at PNC, wrote in an e-mail on Wednesday.