After Standard and Poor's historic downgrade of the U.S.'s credit rating to AA-plus from triple-A, fears are growing that other countries may be next, most notably France, which is facing big costs from a bailout of troubled Euro zone countries.
But the global head of sovereign ratings at S&P says the agency does not have a target list and will downgrade ratings as and when it sees deteriorating economic performance or debt burdens.
"We don't have a hit list, we've obviously taken a number of rating actions in the Euro zone going back a number of years, that's still an unfolding story which we're watching very closely," David Beers told CNBC on Monday.
Beers also said that based on the negative outlook assigned to the U.S., the country could face another downgrade within 6 months to 2 years.
"That will turn on whether or not (the debt) agreement is fully implemented and perhaps to what extent how robust the economic recovery continues to be or if it continues to lag," Beers said.
Beers also defended S&P's decision to downgrade the U.S., despite the discovery of a $2 trillion error in the firm's calculation of the projected debt to GDP ratio for the U.S.
"It is a complete mis-characterization on the Treasury's part about what happened in that highly technical discussion," Beers said. "These are large numbers...(but) even with these adjustments, the debt burden is rising so the substance of what we're saying has not changed."
According to S&P's calculations, the total U.S. public debt, which includes local, state and federal government debt, will be $11 trillion this year, and will rise to $14 trillion in 2015 and to $20 trillion by 2021. Beers said the firm had to cut the rating because the agreement in Congress would slow this growth in debt, but not prevent it.
"This agreement scarcely even touches the entitlements [which are] the biggest part of the budget: medicare, and medicaid, and social security, which everyone knows are where the biggest cost in demographic pressures are in the budget that will continue to drive these expenditures going upwards, going forward," he said.