The path to a debt deal took too long and was too divisive, and lawmakers must now work together to strengthen the country's fiscal position and spur growth, White House spokesman Jay Carney said on Saturday.

"It is important that our elected leaders come together to strengthen our economy and put our nation on a stronger fiscal footing," Carney said in a statement a day after ratings agency Standard & Poor's downgraded the United States' credit rating for the first time.

The White House said the deal to cut spending and raise the debt ceiling, sealed with the nation near default after months of fractious negotiations between the Obama administration and Congress, was "an important step in the right direction."

"Yet the path to getting there took too long and was at times too divisive," Carney said. "We must do better to make clear our nation's will, capacity and commitment to work together to tackle our major fiscal and economic challenges."

He also defended President Barack Obama's push for a "grand bargain" of spending cuts and tax hikes that Republicans and many of his fellow Democrats opposed, saying it would have yielded substantial deficit reduction but required compromise and cooperation from all sides.

Carney said Obama would over the coming weeks strongly encourage a bipartisan committee tasked with finding budget cuts under the agreed debt deal "to put our common commitment to a stronger recovery and a sounder long-term fiscal path above our political and ideological differences."