Embedded Player The credit rating company Standard & Poor's has issued a negative warning on the triple-A credit rating of the United States. S&P says the U.S. has not come up with a credible plan to address fast-rising deficits and mounting debt. S&P warns there's a 1-in-3 chance that it could downgrade the U.S. top credit rating within two years. Markets were down sharply on the news.