Russia has hit back at claims by the White House that Vladimir Putin was directly involved in cyber attacks designed to influence the outcome of the US election.
“At this point they need to either stop talking about this or finally present some sort of proof,” Mr Putin’s spokesman, Dmitry Peskov, told journalists during a visit to Japan.
“Otherwise this looks extremely scurrilous.”
He was speaking after President Barack Obama said America would respond to the attacks at a “time and place of our choosing”.
Whenever a foreign government tried to interfere in US elections, the nation must take action – “and we will”, Mr Obama told NPR News.
“Some of it may be explicit and publicised, some of it may not be,” he said. “But Mr Putin is well aware of my feelings about this, because I spoke to him directly about it.”
On Thursday the Obama administration suggested President Putin personally authorised the hacking of Democratic officials’ email accounts in the run-up to the election and said it was “fact” that such actions helped Donald Trump’s campaign.
The information on Mr Putin’s alleged involvement reportedly came from spies and diplomatic sources.
Russia has denied state-sponsored hacking to tip the balance towards Mr Trump, who is seen as more pro-Russia than his Democratic rival Hillary Clinton.
Mr Putin’s spokesman previously dismissed the latest claims as “laughable nonsense”.
In October, the US government formally accused Russia of cyberattacks and President Obama last week ordered a review by intelligence agencies, set to be completed before he leaves office on 20 January.