"There were tensions up until 30 minutes ago," he said at a news conference shortly after the agreement was reached. "A page was turned today."
Obama suggested that some of the tension was merely a product of the media.
"I know that in the days leading up to the summit, some of the, you in the press, some commentators confused honest and open debate with irreconcilable differences," he said. "But after weeks of preparation and two days of careful negotiation, we have agreed on a series of unprecedented steps to restore growth and prevent a crisis like this from happening again."
White House officials said that behind the scenes there is much more agreement than differences, despite the fiery rhetoric from some world leaders in the days leading up to the summit.
Leading the charge against further government stimulus were the leaders of France and Germany, who pushed for an even stronger worldwide regulation of banks and hedge funds, something Sarkozy called "non-negotiable."
Having already passed stimulus packages with extensive social spending programs, many European countries do not want to take on even more debt.
President Luiz Inacio Lula de Silva of Brazil said the summit would be a "spicy" affair and blamed the financial crisis on the "irrational behavior of people who are white and blue-eyed."
Today Obama greeted the Brazilian leader with effusive praise.
"That's my man, right here, love this guy. He's the most popular politician on Earth. It's because of his good looks," Obama said.
Administration sources said that one of the interesting dynamics playing out here is the rhetoric of these G-20 leaders versus the reality of what they and their representatives are saying behind the scenes.
"I was in Brazil last week," Brown said Wednesday, "and I think President Lula will forgive me for saying this -- he said to me, 'When I was leader of the trade unions, I blamed the government. When I became leader of the opposition, I blamed the government. When I became the government, I blamed Europe and America.' And he recognizes, as we do, that this is a global problem."
Obama alluded to this as well when asked about the heated words coming from the leaders of France and Germany against his push for more global stimulus.
"There have been differences in terms of how should that stimulus be shaped. There have been arguments, for example, among some European countries that because they have more of a social safety net, that some of the countercyclical measures that we took -- for example, unemployment insurance -- were less necessary for them to take," the president said.
"But the truth is ... that's just arguing at the margins. The core notion that government has to take some steps to deal with a contracting global marketplace and that we should be promoting growth, that's not in dispute," he said.
ABC News' Christophe Schpoliansky contributed to this report