French President Nicolas Sarkozy had also said at a press conference after the summit that the euro zone was going through the deepest crisis since its creation.
"Today we face an attack on the whole Europe, not just Greece. We had to respond with community mechanisms, not just bilateral loans as it was the case with Greece," he said.
Sarkozy warned that if the euro zone defaulted, everybody would suffer, including the non-euro countries.
Finance ministers of the euro zone activated an 110-billion-euro (146-billion-U.S. dollar) aid package to Greece on May 2. But the package has failed to allay fears of contagion of the Greek debt crisis.