The White House was hoping to avoid public flare-ups at the summit, although officials are that Obama will be facing a tougher audience than the last time he went to Europe as a candidate when he drew huge adoring crowds in Germany.
Obama still remains popular abroad and Europeans have applauded him for reversing many of the most controversial policies of President George W. Bush, including his move to close the Guantanamo Bay prison in Cuba, ending aggressive interrogation techniques and outlining a plan to withdraw troops from Iraq.
Bill O'Reilly of Fox News show "The O'Reilly Factor" told "Good Morning America" today that Obama will have make a special effort on the issues of the global economy and help with Afghanistan.
"President Obama has to convince the Europeans that are urgent: No 1, to cooperate with America economically, to stop the nonsense and try to stabilize. If we go down, they go down.
"The second thing, Afghanistan. These pinheads in Europe, what do they think is going to happen?" O'Reilly told "GMA." "If we say to them, okay you're not going to help out NATO or our forces in Afghanistan, well the Taliban is going to come back in and it will be a replay of 9/11."
At the heart of the eight-day, five-country trip, Obama's first overseas as president, is the G20 summit where European concerns over the U.S. economy will be front and center.
Besides forging an economic alliance at the summit, Obama has two other major challenges during this whirlwind European trip:
Rally European allies behind his recently outlined strategy for Afghanistan and get them to commit to send more troops.
Rebuild the international confidence in the United States that was shaken during the eight years of the Bush administration.
The biggest point of disagreement heading into the summit is how best to stabilize and grow the global economy and there are wide differences in the approaches favored by the G20 leaders.
Obama has urged foreign governments to spend more in order to spur economic growth, while European leaders have preferred greater regulation to get the economy to bounce back.
The president will be joined by his wife, first lady Michelle Obama, who will have her own schedule of events including a visit to an all-girls school in London; a tour of a London health facility with Sarah Brown, Britain's first lady; and events with other NATO spouses in France.
Obama and the first lady will pay a courtesy call to Queen Elizabeth II of England at Buckingham Palace.
First up for Obama is the G20 economic summit, made up of leaders from 19 major and developing nations and the European Union. The G20 nations represent more than 85 percent of the global economy, about 80 percent of world trade and two-thirds of the world's population.
Brown, the summit's host, is pushing for a united global economic front.
"We can transform the summit from just an annual meeting into an unstoppable progressive partnership to secure the global change the world needs," Brown said.
The goal for the meeting is twofold: agree on a way forward to manage the current global economic crisis and develop a plan to prevent future crises.