LEADERS of major industrial economies meet this weekend to try to head off a full-blown crisis in Europe where fears are growing that Greece could leave the euro zone bloc, threatening the future of the common currency.President Barack Obama, the G8 host, has urged European leaders repeatedly to do more to stimulate growth, fearing contagion from the euro crisis that could hurt the U.S. economy and his chances of re-election in November.British Prime Minister David Cameron, who has been increasingly vocal in urging Europe to do more to resolve the debt woes, will tell leaders they must work together to stop the region’s economic crisis from spreading worldwide, an aide said.No economic policy decisions are expected from the talks but officials said Obama hopes to promote a discussion on a comprehensive approach to resolving the crisis.He will seek to cement a bond with France’s new leader at the White House later on Friday before heading to Camp David for the talks.Francois Hollande, sworn in this week as French president, has already made waves by challenging Europe’s austerity focus and saying he will pull French combat troops from Afghanistan by the end of this year.Obama, 50, may use their introductory meeting in the Oval Office to encourage the 57-year-old Socialist to rethink his Afghanistan plans that put France on an earlier exit timetable than other NATO allies.