Standard & Poor's is reconsidering its decision to downgrade the United States' AAA credit rating after the government challenged the calculations upon which its decision was based, CNBC reported on Friday.

Both CNBC and CNN reported the ratings agency served the Obama administration with a notice that it planned to downgrade the country's ratings.

Quoting a government source, CNBC said S&P miscalculated the U.S. debt-to-GDP ratio in its decision process, based on a misreading of what the correct congressional baseline was.

(Reporting by Walter Brandimarte)