The U.S. sovereign rating should be derived from the viewpoint of its creditors, said Guan Jianzhong, chairman of Dagong Global Credit Rating, the Chinese ratings agency which recently downgraded the U.S.
"In the past we were relying on the three U.S. ratings agencies to make bond buying decisions. But it's more and more obvious that they represent the United States, which is the debtor's interests," Guan said. "It's not reliable," he added.
"The gap between debt levels and fiscal revenue gets bigger and bigger," Guan said. "The world sees this. But credit agencies of the debtor country choose to ignore it or don't make assessments based on these facts."
Dagong, one of China's top four ratings agencies, cut its rating on U.S. sovereign debt to "A-" from "A" last week, maintaining a negative outlook. Dagong has a similar ratings scale to S&P and Fitch, with "AAA" marking the highest rating.
China is the biggest foreign holder of U.S. government debt. At the end of July, China held $1.28 trillion in Treasurys, accounting for roughly 22.8 percent of all foreign holdings of U.S. government debt.
"The world now cares more about ratings from creditor nations. They are more truthful and reliable, and they represent creditors' interests to uncover credit risks," he said. "It should also become a reference or guidance for big creditor nations like China," he said.