Europe's sovereign debt crisis could have "significant systemic effects" on the eurozone, Italy's central bank chief, and the next European Central Bank chief, Mario Draghi said today.

"In the eurozone, the sovereign debt crisis in three countries, which together represent six percent of the area's GDP, has the potential to exert significant systemic effects," Draghi said at a central bank conference.

Greece, Ireland and Portugal have all agreed bailouts in recent months, raising concern about potential contagion in other parts of eurozone.