In a historical first, the US government has officially accused Russia of orchestrating cyber attacks on the country. A government statement on Friday said only the senior-most Russian officials could have authorized the cyber warfare aimed at interfering in the November 8 elections.
The US statement said the Russian attacks were directed against the Democratic party organisations ahead of the election. With the race entering its final phase, Democrat Hillary Clinton is leading Republican and alleged Russophile Donald Trump.
"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.
The Obama administration is considering retaliatory steps against Russia, Reuters said, citing senior officials.
The data thefts and infiltrations carried out by the Russians are intended to interfere with the US election process, the statement added.
However, Russia immediately swatted down the American allegations as "nonsense," according to the Interfax news agency.
A hacker who named himself Guccifer 2.0 had owned up the responsibility in July for the release of documents that revealed the inner workings of the Democratic Party. The US Department of Homeland Security said the method of the attack was consistent with the methods and motivations of Russian-directed efforts.
The Democratic National Committee had disclosed intrusions into its systems in June and blamed Russia for the attacks.
Relations at the lowest ebb
Russia had dismissed the US view that Moscow was behind the attack saying it was merely the poisonous anti-Russian" rhetoric from Washington".
The hacked documents had revealed that Democratic Party officials were biased against Clinton's rival Bernie Sanders in the race for the party nomination.
Officially naming Russia as the state actor behind direct cyber attacks on the country has come at a time when relations between the two powers are at the lowest ebb following the unraveling of the Syrian peace deal.
On Friday, Secretary of State John Kerry said Russia's actions in the Syrian civil war called for a war crimes probe.
Lawmakers from both sides of the political divide in the US welcomed the government move to come down heavily on Russia.