Bloomberg give current ratings by Standard & Poor's, Moody's and Fitch.

• Hit the yellow GOVT key, type TK, then hit GO.
• Select desired country from the menu, then hit GO.
• Select desired security from the list.  Note that it may be necessary to drill down through more than one menu.
• Type CRPR, then hit GO.
• The ensuing display shows current ratings (historical ratings may be available).

Standard & Poor's RatingsDirect (available from Capital IQ) gives ratings and analysis.

• Hover over RatingsDirect and select  Credit Research
• Search for the Country name as a keyword. 

CountryData.com provides ratings calculated by The PRS Group.  Includes data from 1984-present.

• In the CRG Risk Ratings box, under Variables select Financial Risk Rating.
• Select Countries, Years, and Months.
• Download to Excel, CSV, or view online.