Russia says US allegations that it ran a hacking campaign to influence the American presidential elections are "reminiscent of a witch-hunt".
Kremlin spokesman Dmitry Peskov told reporters Moscow was tired of the accusations.
He said a report released by US intelligence agencies detailing the allegations was groundless.
It is the first official reaction from Russia since President-elect Donald Trump received the report on Friday.
The unclassified report alleges Russian President Vladimir Putin ordered the hacking of Democratic Party emails to damage Donald Trump's Democrat rival, Hillary Clinton, and influence the US election.
In his comments on Monday, Mr Peskov said Russia "categorically denied that Moscow had been involved in any hacking attacks".
"Groundless accusations which are not supported by anything are being rehearsed in an amateurish, unprofessional way. We don't know what information they are actually relying on."
The claims amounted to a "witch-hunt", he added.
Trump softens position
Mr Trump repeatedly rejected the hacking claims after winning the November presidential election, but his incoming chief of staff, Reince Priebus, told Fox News Sunday [http://www.radionz.co.nz/news/world/322027/trump-accepts-russia-role-in-us-election-hack the President-elect had accepted the findings of the report].
"He's not denying that entities in Russia were behind this particular campaign," Mr Priebus said.
He did not clarify whether Mr Trump believed the report's assertion that Mr Putin directly ordered the hack.
US National Intelligence Director James Clapper, CIA Director John Brennan and FBI Director James Comey presented the report to Mr Trump on Friday.
Mr Trump said he would ask, within 90 days of taking office, for a plan on how to stop cyber attacks.
He declined to single out Russia, instead saying it was one of several countries, outside groups and people who were "consistently trying to break through the cyber infrastructure of our governmental institutions, businesses and organisations".
With less than two weeks until his inauguration, Mr Trump is under pressure from both Democrats and Republicans to respond to the allegations.
President Obama has expelled 35 Russian diplomats from US soil over the hacking. Russia said it would not reciprocate.
Key findings of report (unclassified version):
- Kremlin had "clear preference" for Mr Trump to win US election, with the goal to "undermine public faith in US democratic process and "denigrate" Hillary Clinton.
- Russian military intelligence hacked into the email accounts of the Democratic National Committee and top Democrats.
- They used intermediaries such as WikiLeaks, DCLeaks.com and Guccifer 2.0 persona to release the information acquired from the hackings.
- They used state-funded propaganda and paid social media users or "trolls" to make nasty comments.
- Russian interference did not affect vote tallies.