"Putin intervened in our elections and succeeded," McFaul posted in his official Twitter account.
Earlier in October, the Department of Homeland Security and the Office of the Director of National Intelligence issued a statement blaming the Russian government for stealing and disclosing information on US political parties and individuals tied to the November elections.
The Russian government has rejected accusations of meddling in US elections saying that it had not received any official evidence from Washington to support the allegations.
In late October, Russian President Vladimir Putin said that Western claims of Russian interference in the US presidential campaign were a mythical problem and hysteria.
According to the latest data, GOP nominee Donald Trump is leading in a number of key states, such as Florida, Ohio and North Carolina, which makes his chances of success significant.
According to The New York Times’ Upshot project, the chances of Trump winning the election now stand at over 95 percent.
