Fitch Ratings has affirmed the United States' credit rating at AAA, giving the world's largest economy a reprieve after it was downgraded by Standard & Poor's little more than a week ago.

Fitch said the outlook for the rating was stable.

"The affirmation of the US 'AAA' sovereign rating reflects the fact that the key pillars of US's exceptional creditworthiness remains intact: its pivotal role in the global financial system and the flexible, diversified and wealthy economy that provides its revenue base," Fitch said in its statement.

"Monetary and exchange rate flexibility further enhances the capacity of the economy to absorb and adjust to 'shocks'."

Reuters