"It's going to be of a size and scope that is necessary to get this economy back on track," he said.
Obama has made it clear that it will be substantially larger than the $175 billion he promised during the presidential campaign.
Incoming White House senior adviser David Axelrod told George Stephanopoulos on "This Week" Sunday that the sputtering economy necessitates a much larger proposal than Obama pitched on the stump.
"He wants a plan big enough to deal with the challenges we face," Axelrod said.
Obama also stressed a recovery plan, "a plan that stabilizes our financial system and gets credit flowing again, while at the same time addressing our growing foreclosure crisis, helping our struggling auto industry, and creating and saving 2.5 million jobs -- jobs rebuilding our crumbling roads and bridges, modernizing our schools, and creating the clean energy infrastructure of the 21st century."
Obama cited the Bush administration's new plan to bolster the banking giant Citigroup and said the company's plight "has made it even more clear that we are facing an economic crisis of historic proportions."
"If we do not act swiftly and boldly, most experts now believe that we could lose millions of jobs next year," Obama warned.
As Obama geared up with his new economic team, Bush and Treasury Secretary Henry Paulson held a brief news conference to explain their decision Sunday to engineer a $306 billion deal to prop up Citigroup, the latest megabank that has needed federal backing to survive.
"We have made these kind of decisions in the past," Bush said while standing outside the Treasury Department. "We made one last night and if need be we will make these kind of decisions to safeguard our financial system in the future."
Bush said he alerted Obama about his plans. "Secretary Paulson is working closely with the president-elect's transition team," Bush said. "It's important for the American people to know that there is close cooperation. It's important for the American people to know that we will safeguard the financial system as the first step necessary for financial -- or for economic recovery."
Obama made clear today that he would not undo bailout commitments made by Bush.
"My administration will honor the public commitments made by the current administration to address this crisis," Obama said.
"It's a move his advisers hope will calm the markets and send a signal that he's on top of the financial crisis," ABC News' chief Washington correspondent George Stephanopoulos told "Good Morning America" today.
But despite Obama's swift efforts in selecting his team and formulating plans, a new ABC News poll shows that only 44 percent of Americans believe Obama will be able to improve the economy significantly. While this might buy the president-elect some time, it does not keep the pressure off him completely.
"The 'cuts and sacrifices' that president-elect Obama advocates will not be made by his friends in Washington, but rather by job creators facing devastating tax increases across America," the Republican National Committee said.
Some Republicans have more faith in his plans.