US accusations that Russia was responsible for cyber attacks against Democratic Party organisations lack any proof and are an attempt by Washington to fan "unprecedented anti-Russian hysteria", the foreign ministry in Moscow said.
"This whipping up of emotions regarding 'Russian hackers' is used in the US election campaign, and the current US administration, taking part in this fight, is not averse using dirty tricks," deputy foreign minister Sergei Ryabkov said on Saturday in comments posted on the ministry's website.
Mr Ryabkov also said Moscow reiterated an offer to Washington, first made last year, to hold consultations on fighting cyber crime together.
The Obama administration formally accused the Russian government on Friday of stealing and disclosing emails from the Democratic National Committee and a range of other institutions and prominent individuals, immediately raising the issue of whether president Barack Obama would seek sanctions or other retaliation.
In a statement from the director of national intelligence, James Clapper Jr., and the Department of Homeland Security, the US government said the leaked emails that have appeared on a variety of websites "are intended to interfere with the US election process."
The emails were posted on the well-known WikiLeaks site and two newer sites, DCLeaks.com and Guccifer 2.0, said to be online personas associated with Russian intelligence.
"We believe, based on the scope and sensitivity of these efforts, that only Russia's senior-most officials could have authorized these activities," the statement said. It did not name Russian president Vladimir Putin, but that appeared to be the intention.
Agencies