Updated

Rating agency Fitch has downgraded the outlook for Russia's credit rating fearing an economic fall-out from the Crimean crisis.

Fitch said in a statement released on Friday that it has revised the outlook for Russia's debt to reflect the potential impact of sanctions on Russia's economy. On Thursday, S&P warned of a potential downgrade, too.

Russian President Vladimir Putin earlier this week signed the treaty to annex Crimea following Sunday's hastily called referendum which overwhelmingly supported that move. The West considers the vote illegitimate.

The Russian stock market has lost more 10 percent this month, wiping out billions in market capitalization.

U.S. President Barack Obama on Thursday ordered economic sanctions against nearly two dozen members of Putin's inner circle and a major Russian bank that provides them support.