Federal Reserve Chairman Ben Bernanke on Friday stopped short of signaling further action to boost growth, but said it was critical for the economy's health to reduce long-term joblessness.

It is clear the recovery from the crisis has been much less robust than we had hoped, he said in remarks prepared for delivery to an annual Fed retreat.

Bernanke said the Fed will meet for two days in September instead of the planned one to mull its options to provide additional monetary stimulus, among other topics.

The Fed chairman said reducing the record high level of workers who have been unemployed for six months or more would help achieve stronger U.S. economic growth.

Under these unusual circumstances, policies that promote a stronger recovery in the near term may serve longer-term objectives as well, he said.

(Reporting by Mark Felsenthal; Editing by Neil Stempleman)