“The recovery may take some time to gather momentum," the Fed chairman said.
Elsewhere, the three presidents said it’s unlikely the Fed will rely on negative interest rates anytime soon.
Treasuries resumed rising and stocks pared losses after the surprise announcement.
"The U.S. economy can operate at a much lower level of unemployment than many would have thought,” he told Congress.
The Fed sees strength in the domestic economy after three rate cuts.
The Chicago Fed president said he's "open minded" on future rate reductions.
The recommendation follows a week of intense upheaval in money markets.
Inflation expectations are on the decline as the Fed shifts towards more accommodation.
N.Y. Fed President John Williams cited a deterioration in U.S. manufacturing.
Three Federal Reserve policy makers voiced their resistance to the notion that the U.S. economy needs lower interest rates.