Federal Reserve Chairman Ben S. Bernanke said the economy is at risk from Europe's debt crisis and the prospect of fiscal tightening in the U.S., while refraining from discussing steps the central bank might take to protect the expansion.

“The situation in Europe poses significant risks to the U.S. financial system and economy and must be monitored closely,” Bernanke said today in testimony to the Joint Economic Committee in Washington. “As always, the Federal Reserve remains prepared to take action as needed to protect the U.S. financial system and economy in the event that financial stresses escalate.”

Bernanke also warned lawmakers that “a severe tightening of fiscal policy at the beginning of next year that is built into current law — the so-called fiscal cliff — would, if allowed to occur, pose a significant threat to the recovery.”