Moody's keeps the Aaa rating pressure on the U.S. and U.K.

As debt mounts in both the U.S. and U.K., the drums are getting a bit louder at Moody's. The credit rating agency is warning both countries to get their debt under control. Yet only under the most pessimistic scenario does the agency think the U.S. could possibly lose its top rating by 2013.

In its latest report, Moody's looks at the 17 countries with its highest Aaa rating and lets those on the edge know that improvement in debt management should start in the next two years.