Amid a flurry of government-backed steps to fortify the U.S. economy, Fed chief Ben Bernanke told lawmakers Tuesday the economy continues to face "numerous difficulties" including turbulent financial markets, rising unemployment and housing troubles.

The Bush administration unveiled the most sweeping plan to overhaul the U.S. financial regulatory system since the Great Depression on Monday, but admitted that the next president's administration will need to hammer out many details with Congress.