The downgrade to what is effectively a determination of default was S&P's final assessment before it pulled coverage (ratings firms are abandoning Russia because of a European Union ban; Moody's Investors Service and Fitch Ratings have also withdrawn ahead of an April 15 deadline).

On April 4, Russia had been due to make a payment of $649 million to holders of two of its sovereign bonds, but the U.S. Treasury blocked the transfer, preventing Russia from using any of its frozen foreign currency reserves to service its debt. The ratings agency said late Friday that it didn't expect investors to be able to convert the ruble payments into U.S. dollars that were equivalent to the original amount due, pushing Russia toward its first default on foreign currency sovereign debt in more than a century.