"It was an error, because Greece entered with false [economic] figures. [Greece] was not ready," Sarkozy said in a televised interview, The Guardian reported Friday.
"We had to face up to all this. If the euro had exploded on Wednesday night, all of Europe would have exploded," Sarkozy said. "If Greece had defaulted there would have been a domino effect carrying everyone away."
"We took important decisions that avoided catastrophe," he said, referring to the international financial rescue package announced in Brussels Thursday.
News of the rescue package, which would increase the firepower of the European Financial Stability Facility from $350 billion to $1.4 trillion, sent shares soaring around the globe.
The rescue package included several key points, including a voluntary loss of 50 percent on Greek debt, current bonds to be swapped for new, 30-year notes at an undetermined interest rate, but with a 20 percent guarantee from the EFSF.
Europe's largest banks will be required to increase their financial cushion against a possible economic downturn.