The leaders of the UK, France, Germany, Italy and Japan and two European Union officials opened the G8 summit with dinner at historic Camp David, a rustic compound tucked away in the Blue Ridge Mountains in rural Maryland, before retiring to private cottages for the night.
Obama, standing at the end of a tree-lined stone path leading to a spacious, cedar-shingled cabin where dinner was held, greeted the leaders one-by-one with hearty hellos before heading inside to break bread.
During their meal, the leaders discussed Iran, Syria, North Korea and the importance of including women in the political process.
Obama welcomed three fresh faces to the G8. France, Italy and Japan all have new heads of state. Hours before the summit kicked off, French President Francois Hollande met with Obama in the Oval Office.
Vladimir Putin, however, skipped the summit — an unexpected pullout that's sparked talk of escalating tensions between the United States and Russia. It's the first time in 38 G8 meetings that a leader has voluntarily chosen to skip it.
The Obama administration had moved the meeting to Camp David from Chicago in part to accommodate Putin. Instead, Russian Prime Minister Dmitry Medvedev took his place.
At the Oval Office, Hollande and Obama discussed Iran and its nuclear ambitions, and even delved into the virtues of cheeseburgers and french fries.
The French president pledged to co-operate with the United States on the European crisis and other issues but said he reminded Obama: "France is an independent country and cares about its independence."
Harper is expected to have a one-on-one chat with Hollande during the summit as Canada and the European Union work toward a free-trade agreement.
British Prime Minister David Cameron, meantime, has been pushing Obama to consider a U.S.-EU free-trade pact.
White House press secretary Jay Carney said Obama would defend at the G8 summit the benefits of stimulus spending to rejuvenate faltering economies rather than the type of austerity measures that have fuelled Europe's latest economic woes.
"The president has long made clear ... that an approach that takes into account the need for further growth and job creation — a balanced approach that includes not just austerity but growth and job creation — is the right approach," he said.
"When we discuss this with our European allies, we can point to some of our own experiences."
In a series of working sessions at Camp David on Saturday, the leaders will tackle not just Afghanistan and the eurozone, but food security in Africa and energy and climate issues. The sessions will take place at round tables not much larger than poker tables to encourage full and frank discussions.
After those sessions wrap up, the leaders then jet off to Chicago for meetings of the North Atlantic Treaty Organization.
In contrast to the peace and quiet of isolated Camp David, where small numbers of protesters gathered several kilometres away in Thurmont, Md., thousands of demonstrators are expected to greet them in the so-called Windy City.
At both the G8 and NATO summits, Afghanistan's economic future and security will be a key topic of discussion.
The U.S. doesn't want to be entirely on the hook for the estimated $4.1 billion it will cost to sustain Afghan security forces when international troops withdraw at the end of 2014.
Australia, Great Britain and Germany have already contributed funds but Canadian officials wouldn't say in advance of the G8 summit whether Ottawa plans to pony up too.
Hollande wants to withdraw all French combat troops by the end of this year, nearly two years ahead of the agreed NATO schedule.
"I made a promise to the French people to the effect that our combat troops would be withdrawn from Afghanistan by the end of 2012," Hollande said he told Obama on Friday.
"That being said, we will continue to support Afghanistan, in a different way. Our support will take a different format, and all of that will be in good understanding with our allies."
The Camp David summit's other dominant focus — Europe's economic crisis — represents a shift for the G8, says the director of the G8 Research Group at the University of Toronto.
It used to be that the G20 focused on the economy while the G8 tackled global security and development issues, said John Kirton. The Camp David summit changes that.
"It's going to be about a G8 strategy for growth which will be smart, sophisticated and, it is to be hoped, it will be sufficiently clear and compelling to convince markets, citizens, voters across the G8 and beyond that it will work," he said.
"So that's new for the G8. It's been many, many years since the G8 has focused like a laser beam on the economy and in containing the great economic crisis that's burgeoning at the moment."
Camp David, with its winding trails and lush woods, has a storied past.
President Franklin D. Roosevelt and British Prime Minister Winston Churchill met at the retreat in 1943 to discuss plans to invade Normandy during the Second World War.
Under Jimmy Carter, Egypt and Israel signed a peace treaty at Camp David. George W. Bush, meantime, was so fond of the retreat that he spent almost 500 days at Camp David throughout his two terms as president.
Part of the appeal is the retreat's tightly controlled location within Catoctin Mountain Park. The public can't get anywhere near Camp David; protesters, indeed, were descending upon Thurmont, six kilometres away, to make their feelings known.
By Saturday, hundreds could line the streets of the town of 6,000 to protest everything from the U.S. government bailout of banks to the American military's use of unmanned drone aircraft. Others will push for nuclear disarmament and civil rights in Ethiopia.