A revision on credit outlook was performed by Standad & Poor's, changing the United States' rating to stable from negative. The financial services company stated reasons including unexpectedly high tax receipts that followed the so-called fiscal cliff of 2012.

Standard & Poor's further said that it is not expecting a debate on the raising of the debt ceiling later in the year.

The agency estimates that the probability of a ratings downgrade is "less than one in three ," considering the performance of the United States economy and a noticeable improvement in tax receipts bringing down the debt levels.

"We believe that our current 'AA-plus' rating already factors in a lesser ability of U.S. elected officials to react swiftly and effectively to public finance pressures over the longer term in comparison with officials of some more highly rated sovereigns and we expect repeated divisive debates over raising the debt ceiling," S&P said.

The government's strides on improving the budgeting system on a long-term basis had improved the outlook of the nation, S&P said.

Standard & Poor's rivals Fitch and Moody's upheld its current AAA rating. Both, however, have negative outlooks when it comes to the country's credits.