Europe has won support from world leaders for an ambitious but slow-moving overhaul of the eurozone.

European countries showed at a Group of 20 summit they were considering concrete steps to integrate their banking sectors, a major reform long sought by the US and other nations.

US Treasury Secretary Timothy Geithner said a stronger framework for a fiscal and banking union to underpin the euro  would help restore Europe's economic growth.

Canadian Prime Minister Stephen Harper, a critic of Europe's progress to date, said the EU now is addressing all the key issues required to get to the root of its crisis, ahead of an EU summit next week.

Financial markets have yet to be convinced.

Spain, the eurozone's fourth-largest economy, risks needing a full-blown international rescue as its longer-term debt yields hover above 7%, a level that has forced other euro countries to seek bailouts.

French President Francois Hollande said he and German Chancellor Angela Merkel were determined that the eurozone come up with its own solutions.

G20 leaders and the International Monetary Fund have pressured Europe to throw more support behind indebted eurozone members and lay out a clear timeline for building financial, fiscal and political union - steps they view as crucial to saving Europe's monetary union.

Greece, Ireland and Portugal have resorted to international bailouts and the eurozone last week pledged up to €100bn to shore up Spain's banking system. But investors see these as stop-gap measures until Europe commits to deep budgetary and political integration.

This would require eurozone nations to give up more sovereignty and share economic risk, steps that EU leaders say will take time among the 17 democracies that share the currency, especially for Germany which would foot the largest bill.

The dangers that Europe's escalating debt crisis would drive the global economy back into recession for the second time in less that four years dominated the summit of G20 leaders of industrialized and developing nations, which represent over 80% of world output.

The World Bank last week lowered its forecast for global growth in 2012 to 2.5% and said developing nations faced a long period of financial market volatility and weaker growth.