Moody's downgrades U.S. credit rating, citing rising government debt

The U.S. credit rating was downgraded by Moody's Ratings on Friday, with the nation's credit score lowered from Aaa to Aa1. 

The downgrade "reflects the increase over more than a decade in government debt and interest payment ratios to levels that are significantly higher than similarly rated sovereigns," the credit rating firm said in a statement on Friday. 

"Successive US administrations and Congress have failed to agree on measures to reverse the trend of large annual fiscal deficits and growing interest costs," Moody's added.