"The US Intelligence Community (USIC) is confident that the Russian Government directed the recent compromises of emails from US persons and institutions, including from US political organizations," reads a joint statement from the US Department of Homeland Security and Office of the Director of National Intelligence on Election Security.
"The recent disclosures of alleged hacked emails on sites like DCLeaks.com and WikiLeaks and by the Guccifer 2.0 online persona are consistent with the methods and motivations of Russian-directed efforts," it added.
"These thefts and disclosures are intended to interfere with the US election process."
The hack into the private emails of the DNC occurred in June. While a number of US officials have suggested, without evidence, that the Russian government was behind the intrusions, this is the first time that Obama administration has officially accused the Kremlin.
Additionally, the statement suggests that "some states have also recently seen scanning and probing of their election-related systems, which in most cases originated from servers operated by a Russian company," but the USIC has not yet blamed these incidents on the Russian government.
In the wake of the accusation, the chairman of the US Senate Cyber Security Subcommittee plans to introduce legislation that would impose new sanctions on Russia.
Moscow has fervently denied any connection to the security breaches.
"But I want to tell you again, I don't know anything about it, and on a state level Russia has never done this," Russian President Vladimir Putin said in an interview with Bloomberg last month.