Standard and Poor's has placed Germany, France and 13 other eurozone members on a negative credit watch, warning they could be hit with downgrades.
"Today's CreditWatch placements are prompted by our belief that systemic stresses in the eurozone have risen in recent weeks to the extent that they now put downward pressure on the credit standing of the eurozone as a whole," S&P said in a statement.
The warning threatened the AAA ratings of Germany, France, the Netherlands, Finland, Luxembourg and Austria.
S&P said it would complete a review of eurozone sovereign ratings "as soon as possible" following the European Union summit on Thursday and Friday on the region's economic crisis.
Depending on the results of that summit, S&P said, "we believe ratings could be lowered by up to one notch for Austria, Belgium, Finland, Germany, Netherlands, and Luxembourg, and by up to two notches for the other governments".
