Treasury Secretary Timothy Geithner on Sunday said the U.S. wasn't in danger of losing its triple-A bond rating, in the wake of a warning from Moody's Investors Services about U.S. treasury-bond rating.

"Absolutely not," Mr. Geithner said in an interview with ABC News's "This Week" when asked about the prospect of the U.S. losing its top rating. "That will never happen to this country."

Bond rating agency Moody's on Wednesday warned that the triple-A rating of U.S. treasury bonds could be in peril unless the U.S. reduces its federal budget deficit or the economy rebounds.

Mr. Geithner noted that when investors were nervous about a global financial crisis, they sought safety in U.S. Treasury securities and the U.S. dollar. "That is a very, very important sign of basic confidence in our capacity as a country to work together to fix these problems," he said.

He said the Obama administration was "deeply serious" about deficit reduction. Mr. Geithner has endorsed the creation of a bipartisan commission that would be charged with recommending ways to reduce the federal deficit over the long haul.