Thirteen Russians have been charged with interfering in the US 2016 election, in a major development in the FBI investigation.
Three of those named have also been accused of conspiracy to commit wire fraud and five have been accused of aggravated identity theft.
The charges were made by Special Counsel Robert Mueller, who is investigating alleged Russian meddling.
Three Russian companies are also named in the indictment.
One of them is the Internet Research Agency, based in St Petersburg, which the 37-page indictment said “had a strategic goal to sow discord in the US political system, including the 2016 US presidential election”.
Speaking at a news conference, Deputy Attorney General Rod Rosenstein said there was no allegation that any American was “a knowing participant in this illegal activity” nor was it alleged that the meddling altered the election outcome.
Mr Trump was briefed on the indictment earlier on Friday, the White House said.
The president later tweeted that his campaign had done “nothing wrong” and again denied colluding with Russia.
He also appeared to acknowledge Russian election meddling – something which he has in the past cast doubt on despite US intelligence agency assessments.
How has Russia reacted?
It called the allegations “absurd”.
“Thirteen people interfered with the US elections?” said Maria Zakharova, a Russian foreign ministry spokeswoman. “Thirteen against the billion-dollar budgets of the security services? Against espionage and counter-espionage, against new developments and technologies? Absurd? Yes.”
As part of the inquiry, former Trump campaign manager Paul Manafort has been charged with conspiring to defraud the US in his dealings with Ukraine, and conspiracy to launder money.
A business associate of his, Rick Gates, was also charged with conspiracy to launder money. A third adviser to the Trump campaign, George Papadopoulos, pleaded guilty to lying to the FBI.
This week President Trump’s former chief strategist, Steve Bannon, was interviewed by Mr Mueller.
Mr Trump has been accused by opponents of trying to interfere with the investigation, which he denies.