In this April 8, 2014, photo, Secretary of State John Kerry appears before the Senate Foreign Relations Committee on Capitol Hill in Washington.
The United States is deploying an economic weapon against Russia that could prove to be more costly than sanctions: the Internal Revenue Service.
As the US attempts to punish Russia for its actions in Ukraine, the Treasury Department plans to start using a new tax law to make it more expensive for Russian banks to do business in the US Congress passed the law in 2010 to curb tax evasion through the use of overseas accounts.
Starting July 1, the law targets foreign financial institutions that don't agree to share information about US account holders with the IRS. Russia had been negotiating an information-sharing agreement with the US. But after Russia annexed Crimea and was seen as stoking separatist movements in eastern Ukraine, Treasury suspended negotiations.