Since the summer of 2009, the economy has expanded at an average annual rate of 2.5%, adding 3.9 million private sector jobs over the last two years, U.S. Treasury Secretary Timothy Geithner said in remarks prepared for a Chicago speech.

"Growth has been led by private demand, including strong gains in investment and exports. The balance sheet of the business sector is exceptionally strong, and the economy as a whole is more productive than before the crisis," he said in remarks to be delivered to the Economic Club of Chicago.

Still the economy faces challenges with high unemployment, a weak housing market and slow growth — legacies of the 2008 financial crisis, he said.

"Our economy is still in the process of deleveraging, dealing with significant household debt, excess investments in real estate and other forms of debt," he said.

— Kerry Curry