Two leading credit rating agencies on Thursday cautioned the U.S. on its credit rating, expressing concern over a deteriorating fiscal situation that they say needs correction. Moody's Investors Service said in a report Thursday that the U.S. will need to reverse an upward trajectory in the debt ratios to support its triple-A rating. "We have become increasingly clear about the fact that if there are not offsetting measures to reverse the deterioration in negative fundamentals in the U.S., the likelihood of a negative outlook over the next two years will increase," said Sarah Carlson, senior analyst at Moody's. Standard & Poor's Corp. on Thursday also didn't rule out changing the outlook for its U.S. sovereign-debt rating because of the recent deterioration of the country's fiscal situation. The U.S. currently has a triple-A rating with a stable outlook at both agencies.