Story highlights An Obama official said Russia was behind a December cyber attack on Ukraine's power grid

Elizabeth Sherwood-Randall made the comments to a gathering of electric power grid industry executives

(CNN) Russia was behind a December cyber attack on Ukraine's power grid that caused widespread power outages, a senior Obama administration official said Thursday.

Elizabeth Sherwood-Randall, deputy Energy Secretary, made the comments to a gathering of electric power grid industry executives, according to an U.S. official familiar with her presentation.

Her comments contrast with the view of other top U.S. intelligence and security officials who say the evidence isn't conclusive enough and that the U.S. government isn't ready to attribute the cyber attack to the Russian government. Other officials who spoke at the Thursday briefing stopped short of Sherwood-Randall's definitive assessment.

A spokeswoman for Sherwood-Randall said she couldn't provide details of the presentation or discuss the highly sensitive information provided. The spokeswoman declined further comment.

U.S. intelligence and national security officials have closely followed the investigation of the Ukrainian grid attack, because they say it represents a first-of-its-kind confirmed cyber-warfare attack affecting civilians. The attack also raised major concerns because the U.S. power grid and other major industrial facilities have many of the same vulnerabilities that were exploited in the Ukraine attack, U.S. officials say.

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