Vladimir Putin personally ordered a campaign that amounted to "propaganda on steroids" as he sought to steal the presidential election from Hillary Clinton, US Senators have claimed.
Thousands of "cyber trolls" based in Russia were said to have pumped out "fake news" targeting voters in key states such as Wisconsin, Michigan and Pennsylvania, all of which Mr Trump won despite being behind in polls.
Kremlin-backed computer operatives even sought to influence Mr Trump himself, flooding his Twitter feed with conspiracy theories when they knew he was online, the Senate Intelligence Committee was told at its first public hearing in Washington.
Mr Putin issued his most emphatic denial so far, calling the accusations that he meddled in the US election "nonsense, endless, and groundless". He said: "Ronald Reagan was talking about taxes once and said 'Read my lips'... Read my lips - no."
The quote was in fact from George H W Bush.
Mark Warner, a Democratic senator who is vice-chairman of the Senate committee, said: "Vladimir Putin ordered a deliberate campaign carefully constructed to undermine our election. There were paid internet trolls working out of a facility in Russia.
US President Donald Trump speaks during an event celebrating Women’s History Month, in the White House. Photo: Getty
"This Russian 'propaganda on steroids' was designed to poison the national conversation in America."
On whether there were links between Russia and Mr Trump's campaign, Mr Warner said: "We are seeking to determine whether there is an actual fire, but there is a great, great deal of smoke."
Giving evidence Clint Watts, a former FBI agent, said: "Russia sought to sideline opponents on both sides of the political spectrum."
Mr Putin said he was ready to meet with Mr Trump and work with him to fight terrorism, and criticised what he called use of the "Russian card" in US politics.
Mr Warner and the panel's chairman, Republican Senator Richard Burr, provided an update on Wednesday of the committee's investigation into activities Russia might have taken to alter or influence the 2016 elections and whether there were any campaign contacts with Russian government officials that might have interfered with the election process.
"There were upwards of 1,000 paid internet trolls working out of a facility in Russia, in effect, taking over series of computers, which is then called a botnet," Mr Warner told reporters on Capitol Hill.
But Mr Putin pointed to the fallout of the scandal in Washington as "proof" that Russia had not interfered in the election, saying that it had made it impossible to plan a meeting with Mr Trump.
"The president is barred from implementing his agenda on health care or international affairs, relations with Russia and we will wait till things stabilise," he told CNBC during a forum on Arctic development in the northern port town of Arkhangelsk.
"At a certain point of time it will come to a close and we will decide when and where the meeting is held," he added.
Earlier yesterday, the Russian foreign ministry hit out at claims one of its diplomats had been identified as a spy with a key role in the alleged influence campaign.
Mikhail Kalugin, the former head of the economic section at the Russian embassy in Washington, was first accused of being a Russian spy by Christopher Steele, a former British intelligence officer, in a dossier on alleged links between the Kremlin and Mr Trump's electoral campaign that was made public in January.
The BBC claimed on Wednesday that US intelligence agencies have now confirmed that Mr Kalugin is a member of the SVR or GRU, Russia's main overseas intelligence branches.
The claim is significant because none of the allegations in Mr Steele's 35-page dossier has yet been verified.
The Senate Intelligence Committee may call Mr Steele to testify about his claims at its hearings into the affair.
Meanwhile, Ivanka Trump said she will become an official unpaid federal employee after Democratic lawmakers said her previously unspecified role advising her father, Mr Trump, raised questions about how she would avoid conflicts of interest.