WASHINGTON – When leaders from eight of the world’s biggest economies meet this weekend outside Washington, the focus will be on how to prevent Europe’s debt crisis from spiraling out of control.

The turmoil in Greece is draining confidence in the 17 countries that use the euro. Borrowing costs are up for the most indebted governments. Depositors and investors are fleeing banks seen as weak. Unemployment is soaring as recession grips nearly half the eurozone countries. And global markets are on edge.

All that forms a tumultuous backdrop as representatives of the G8 countries — the United States, Germany, France, Britain, Japan, Russia, Italy and Canada — head to Camp David. Standing in the way of a breakthrough are disagreements over how to bolster Europe’s economy and avoid a broader catastrophe.

In advance of the talks, German Chancellor Angela Merkel struck a conciliatory note this week. She said in a television interview that she was open to measures to help stimulate Greece’s economy as long as the country honors its commitments to shrink its debts.

U.S. Treasury Secretary Timothy Geithner applauded the softer tone emerging among European leaders.

“You are seeing them talk about a better balance between growth and austerity, meaning a somewhat more gradual, softer path toward restoring fiscal sustainability,” Geithner said.

The shift shows that European leaders recognize that countries can’t increase their economic growth if they’re forced to focus solely on cutting spending and reducing debts. Geithner said European countries would benefit from investment in public works projects, such as roads and schools.

At this weekend’s talks, non-European leaders will seek assurances that European leaders could contain the damage from a banking meltdown in Greece. They worry about a panic that could spill into Portugal, Spain and other indebted European countries — and to nations outside the continent whose banks are connected to Greek banks.

“If there was a bank run in Greece … would they know how to prevent it from spreading to other countries?” asked Jacob Kierkegaard, a research fellow at the Peterson Institute for International Economics.

The meetings begin this evening with an economics-focused summit at Camp David, the presidential retreat in Maryland’s Catoctin mountains. They will end Saturday evening. Most of the officials will join a larger group of international leaders in Chicago for a national-security oriented NATO summit Sunday and Monday.