U.S. Secretary of State John Kerry has accused Russia of not taking "a single concrete step" to de-escalate the Ukrainian crisis.
In a blistering attack Thursday, Kerry said Russia has failed to uphold the four-party deal it signed last week to ease tensions in eastern Ukraine.He said Moscow's refusal to restrain pro-Russian separatists there will be "an expensive mistake," saying more sanctions are possible.
On Friday, credit agency Standard and Poor's cut Russia's credit rating to BBB- , underscoring the risks of Russia's policies in Ukraine.
