US officials have officially accused Russia of attempting to influence the 2016 election by hacking the Democratic National Committee and other political organisations.
The Department of Homeland Security and the Office of the Director of National Intelligence issued the statement late Friday afternoon amid months of speculation that Moscow was the source of the recent hacks.
"The U.S. Intelligence Community (USIC) is confident that the Russian Government directed the recent compromises of e-mails from US persons and institutions, including from US political organisations," the statement from the two agencies said.
The announcement comes as yet another blow to relations between the US and Russia, as Secretary of State John Kerry called for a war crime investigation for the nation's continued airstrikes in Syria on Friday morning. The State Department announced earlier this week that communcation had been halted as they broke a ceasefire agreement reached between Mr Kerry and his Russian counterpart, Sergey Lavrov, in September.
White House officials declined to say whether the formal accusation of Russia's involvement in the hacks would result in sanctions. A senior Obama administration official told the Associated Press that the US would respond "at a time or place of our choosing", but retaliation would likely not occur publicly.
The statement said that the recent hacks posted to WikiLeaks and DCLeaks.com, as well as by the online persona Guccifer 2.0, were consistent with Russian hacking methods.
"These thefts and disclosures are intended to interfere with the US election process," the statement said.
"We believe, based on the scope and sensitivity of these efforts, that only Russia's senior-most officials could have authorized these activities."
On Saturday, the Russian Foreign Ministry said the US accusations lacked any proof and were an attempt by Washington to fan “unprecedented anti-Russian hysteria”.
“This whipping up of emotions regarding 'Russian hackers' is used in the U.S. election campaign, and the current US administration, taking part in this fight, is not averse to using dirty tricks,” Deputy Foreign Minister Sergei Ryabkov said in comments posted on the ministry's website.
Russian President Vladimir Putin has also previously denied any connection to the alleged hacks.
“I know absolutely nothing about it,” he told Bloomberg News in September. “Russia has never done anything like this at the state level.”
He added: “I could never even imagine that such information would be of interest to the American public.”
But the USIC says Russia has attempted to influence public opinion through their hacks across Europe and Eurasia.
California Rep Adam Schiff celebrated the public recognition of the Russian-sponsored hacks on Friday.
"We should now work with our European allies who have been the victim of similar and even more malicious cyber interference by Russia to develop a concerted response that protects our institutions and deters further meddling," Mr Schiff said.
The DNC revealed that they had been hacked in June. A cybersecurity firm contracted by the DNC found that the hacks were carried out by Russian actors. The disclosure by the party was followed by a massive data dump of internal DNC emails that resulted in the resignation of former chairperson, Florida Rep Debbie Wasserman Schultz.Reuse content