NEW YORK — Fitch Ratings affirmed its AAA credit rating for the United States on Tuesday and said the outlook is stable, citing the nation’s central role in the global financial system and the flexible, diverse economy.

Fitch had put the rating under review after lawmakers reached a compromise Aug. 2 on a debt-limit agreement that prevented a U.S. default. On Aug. 5, Standard & Poor’s cut its U.S. credit rating to AA+ from AAA, saying lawmakers failed to cut spending enough to reduce record deficits. Moody’s Investors Service affirmed its top U.S. ranking last week.

Since the U.S. downgrading by S&P, the New York-based subsidiary of McGraw-Hill Cos., the yield on the 10-year Treasury note, a benchmark for everything from home mortgages to car loans, has declined to as low as 2.03 percent from a high this year of 3.77 percent. Interest rates on American bonds are lower today than on most of the countries with AAA S&P ratings, and the Treasury recently financed its outstanding debt at the lowest cost ever.

The U.S. may be placed on negative outlook, indicating more than a 50 percent probability that the nation will be downgraded in the next two years, should weaker than estimated economic growth or a failure by a congressional committee to enact $1.2 trillion in budget cuts spur projected debt levels to rise more than estimated, Fitch said Tuesday A one-step downgrade is “less likely.” Lawmakers’ agreed Aug. 2 to put in place a plan to enforce $2.4 trillion in spending reductions over the next 10 years.

“The Fitch reassessment of waiting to see what the committee comes up with is prudent and also appropriate given the mandate of the” committee, said Christian Cooper, head of U.S. dollar derivatives trading in New York at Jefferies Group.

The Aug. 2 law reduces the deficit by a minimum of $4.1 trillion in the coming decade, such that the fully implemented plan “would bring U.S. public finances materially closer to a sustainable path,” Fitch said.