U.S. Treasury Secretary Timothy Geithner said on Thursday that austerity measures alone would not be enough to fix debt problem and meet challenges ahead.

"A credible strategy for economic growth requires a willingness to do things, not just to cut things," Geithner said in prepared remarks for an event at the Greater Baltimore Committee held in Baltimore, a city in the U.S. state of Maryland.

He said the economic challenges for the United States, including a still healing economy and threat from European debt crisis, can only be met with an economic agenda that focuses on strengthening economic growth and a balanced approach to restoring long-term fiscal sustainability.

"These challenges cannot be solved by an economic agenda of severe, immediate austerity, combined with deep, permanent cuts in education and the safety net for retirees ..." Geithner refuted the GOP's call for spending cuts without tax increases.

He defended President Barack Obama's plan to combine tax reforms with spending savings, saying it will reduce deficits without cutting deeply into the social security programs.

Geithner also said the country cannot afford to borrow money to extend Bush tax cuts for the top 2 percent wealthy people, which would amount to 1 trillion U.S. dollars for the next decade.

"Tax cuts don't pay for themselves. You have to pay for them," he added.

The U.S. federal government is likely to hit its debt ceiling after the November election. Geithner said the Treasury has some measures to manage into early 2013.