Federal Reserve Chairman Ben Bernanke today stopped short of signaling further action to boost the U.S. recovery, Reuters reported, but he said reducing unemployment is critical for the economy’s health.

Bernanke’s speech at an annual Fed conference here met with a mixed reception in financial markets, where some had hoped he would make a clear case for a further easing of monetary policy.

Stocks initially fell, with the blue chip Dow Jones industrial average dropping as much as 220 points. By mid-day, however, the Dow was in positive territory.

Bernanke expressed long-term optimism but made it plain that the central bank found recent developments troubling. He said the policy-setting Federal Open Market Committee would expand its September meeting to two days from one to discuss its options.

However, he also stressed that most of the burden for ensuring a solid foundation for long-term growth lay at the feet of the White House and Congress. Bernanke said investor concerns about Europeean debt and political fights on the U.S. budget had harmed growth prospects.