“The pressure on the U.S. rating, if anything, is increasing,” said David Riley, managing director of Fitch Ratings’ global sovereigns division. “We thought the 2011 crisis was a one-off event …. if we have a repeat we will place the U.S. rating under review.”

Fitch already has a negative outlook on the U.S. and has said it will make a decision on the rating this year, regardless of how the debt ceiling discussions pan out. The U.S. government reached its statutory debt limit of nearly $16.4 trillion at the end of 2012 but has engineered extraordinary measures that should see it through February…

Riley warned that the different arms of the U.S. government still have a number of issues to address. As well as increasing the debt ceiling, they have to agree to spending cuts that were delayed as part of the ‘fiscal cliff’ agreement and back measures to avoid a government shutdown, potentially in March.