[UPDATE]G8: Trans-Atlantic trade talks key; Putin, Harper trade barbs Marine One takes off with U.S. President Barack Obama, U.S. First Lady Michelle Obama and their daughter Malia from the South Lawn of the White House in Washington on June 16, 2013. Obama is traveling to Northern Ireland to take part in the G8 Summit. UPI/Joshua Roberts/Pool ENNISKILLEN, Northern Ireland, June 17 (UPI) -- Discussion of trans-Atlantic trade at the Group of Eight summit is a "powerful way" to ignite world economies, British Prime Minister David Cameron said Monday. The main point of the summit "is to fire up our economies and drive growth and prosperity around the world," Cameron told a news conference. And there is no more powerful way of doing this than boosting trade. Besides Cameron, U.S. President Barack Obama, European Commission President Jose Manuel Barroso and European Council President Herman Van Rompuy, commented on the proposed Transatlantic Trade and Investment Partnership talks that are to begin in earnest in Washington July 8. A trade deal "could add as much as a $157 billion to the EU economy, $125 billion to the U.S. economy and as much as $133.4 billion to the rest of the world," Cameron said. Obama characterized the trade talks as "groundbreaking." "It would increase exports, decrease barriers to trade and investment," he said, noting the deal would support "hundreds of thousands of jobs on both sides of the ocean." Obama said trade between the European Union and the United States "makes up nearly half of global gross domestic product." Soon after their arrival in Belfast, President Obama and first lady Michelle Obama spoke at a town hall meeting of young people at the Belfast Waterfront. Obama told the young people in the audience they were providing a "blueprint" to other countries afflicted by violence, that a lasting peace was possible and that "hope is contagious." "[You] set an example for those who seek a peace of their own," Obama said. And they're groping to find a way to discover how to move beyond the heavy hand of history, to put aside the violence. They're studying what you're doing. And they're wondering, perhaps if Northern Ireland can achieve peace, we can, too. You're their blueprint to follow. You're their proof of what is possible -- because hope is contagious. Russian President Vladimir Putin scolded the West before the G8 sessions for for considering arming Syrian rebels who he said eat human organs. Putin said his country, by contrast, supplied weapons to Syrian President Bashar Assad's "legitimate government" -- a government Canadian Prime Minister Stephen Harper said was run by "thugs." Obama was to meet privately with Putin. Putin spoke at a news conference with British Prime Minister David Cameron. Harper, speaking at a reporters briefing in Dublin, Ireland, before arriving in Northern Ireland, castigated Putin for supporting the Assad regime and even suggested Putin didn't have the same status at the table as the seven leaders of some of the most advanced Western democracies. Let's be blunt. That's what this is -- the G7 plus one.