He noted that Republican President George W. Bush and first lady Laura Bush had invited Obama and his wife Michelle to the White House on Monday and that the Bushes offered to do all they could to help with Obama's transition to the White House.
"This speaks to a fundamental recognition that here in America we can compete vigorously in elections and challenge each other's ideas, yet come together in service of a common purpose once the voting is done," Obama said in the Democratic Party's weekly radio address.
"And that is particularly important at a moment when we face the most serious challenges of our lifetime," he said.
Obama noted that jobless figures released on Friday showed a 10th straight month of decline, bringing the total number of unemployed Americans to about 10 million.
"Tens of millions of families are struggling to figure out how to pay the bills and stay in their homes," Obama said. "Their stories are an urgent reminder that we are facing the greatest economic challenge of our lifetime, and we must act swiftly to resolve them."
Obama said he and his transition economic advisory board -- a well-regarded group of America business leaders, former top Washington officials and economic experts -- discussed the economic challenges at a meeting on Friday and started developing a series of policies to address the crisis.
"While we must recognize that we only have one president at a time and that President Bush is the leader of our government, I want to ensure that we hit the ground running on January 20th because we don't have a moment to lose," said Obama.
The first-term senator from Illinois, who excited crowds across the country with his promise for change and attacks on the Bush administration for causing the economic crisis, which is now global, vowed to help working class families and to stem the problems before they get worse.
He said the country "can't afford to wait" on moving forward with his priorities like clean energy, reforming health care, improving education and tax relief for middle class families.
"I do not underestimate the enormity of the task that lies ahead," said Obama. "We've taken some major actions to date, and we will need further actions during this transition and subsequent months."
"Some of those choices will be difficult, but America is a strong and resilient country. I know that we will succeed if we put aside partisanship and work together as one nation. And that is what I intend to do."