Standard &Poor's on Thursday revised the outlook for the Russian Federation to negative from stable on rising geopolitical and economic risks.

The rating agency affirmed Russia's BBB foreign currency rating.

"The outlook revision reflects our view of the material and unanticipated economic and financial consequences that EU and U.S. sanctions could have on Russia's creditworthiness following Russia's incorporation of Crimea, which the international community currently considers legally to be a part of Ukraine," S&P said in a statement.

U.S. President Barack Obama announced sanctions on Thursday against prominent Russians including close allies of President Vladimir Putin, as Moscow raced to complete its annexation of Crimea and built up its forces in the region.

—Reuters