One of Ben Bernanke's consistent messages to Congress has been the need to prevent the economy from falling off a "fiscal cliff" at the end of the year. That's when tax increases and deep spending cuts will take effect unless Congress reaches a budget agreement.

Many economists warn that another recession would follow.

On Tuesday, the Federal Reserve chairman sounded his warning anew. Yet he stopped short of telling lawmakers what their priorities should be in pursuing a budget deal.

"I don't have a specific recommendation, other than to think not just about the individual policies, but of the collective impact," Bernanke said.

"Congress is in charge here, not the Federal Reserve," he said.