The U.S. economy has "walked some substantial distance back from the abyss" and no longer at risk for collapse, one of President Obama's top economic advisers said Friday.

"We were at the brink of catastrophe at the beginning of the year but we have walked some substantial distance back from the abyss," National Economic Council (NEC) Chairman Lawrence Summers told the Peterson Institute in a speech Friday. "Substantial progress has been made in rescuing the economy from the risk of economic collapse that looked all too real 6 months ago."

Summers, a former Treasury secretary who's been occasionally rumored to be a contender to take over as Federal Reserve chairman one day, said the economy was in "free fall" when the Obama administration took office in January. Summers said that, at the time, there seemed to be "no apparent limit on how much worse things could get."

The NEC director defended the administration's actions to address the economic difficulties in place when they took office, adding that their goal is to wind down an asset bubble model of growth and replace it with a more export-oriented and environmentally friendly economy.

"Yes, the President has an ambitious agenda," Summers said. "But it is an agenda comprised of measures that lay a foundation for future prosperity and for the confidence on which the current recovery depends."