He also said during a joint press conference with the British Prime Minister Theresa May that his administration was "tougher on Russian Federation than anybody". Mueller, as has been his practice, did not attend the announcement.
Mr Mueller's 29-page indictment revealed the scope of the Russian.
The indictment, which alleges a wide-ranging conspiracy involving sophisticated hacking and staged releases of documents, raises the stakes for a summit next week between President Trump and Russian President Vladimir Putin. Rosenstein said he briefed Trump earlier this week on the charges.
The indictment includes 11 criminal counts and one forfeiture allegation.
Mr Rosenstein also said that the hackers were able to steal information on 500,000 voters from a state election board website.
Rosenstein said the internet "allows foreign adversaries to attack Americans in new and unexpected ways".More news: Meghan Markle Will Support Friend Serena Williams This Weekend At Wimbledon
"There's no allegation in this indictment that any American citizen committed a crime". At the same time, it admitted that the alleged hacking attack in fact did not eventually affect any votes.
"What impact they may have had, what their motivation may have been independently of what's required to prove this offence, is a matter of speculation". It was the first by Mueller that directly charges the Russian government with meddling in the election, which Trump unexpectedly won. With the new indictment, his office has filed charges against 32 people on crimes ranging from hacking to money laundering to lying to the Federal Bureau of Investigation. Twenty-six of those charged are Russians who are unlikely to ever be put on trial in the United States.
Five people have pleaded guilty, including former Trump campaign officials Paul Manafort and Mike Flynn, who was sacked as national security adviser after he admitted lying about his contacts with Russians on the campaign trail.
Stone was an adviser to Trump during the campaign and has clearly been investigated by Mueller's team and the grand jury, after several of his business associates received requests for documents or to testify before the grand jury.
Trump and his allies have also vehemently criticized Sessions for the recusal. Given that we are mere months away from a massively important state and local midterm election, you'd think people would be more concerned about protecting us from the continuing threat of Russian interference.More news: Kerber defeats Williams to claim Wimbledon crown
President Donald Trump has yet to directly respond to the newly announced indictments of Russian intelligence officers for hacking Democrats during the 2016 election, but his personal lawyer, Rudy Giuliani, cheered the results as "good news for all Americans".
The indictment of 12 Russians for allegedly hacking the Democratic Party in 2016 appear to be politically motivated, with the goal of spoiling the upcoming Helsinki summit, the Russian Foreign Ministry said.
Democratic lawmakers and Republican maverick John McCain have called on Trump to cancel the summit following the indictments, with Senate Minority Leader Chuck Schumer remarking "Glad-handing with Vladimir Putin on the heels of these indictments would be an insult to our democracy".
While U.S. intelligence agencies have long blamed Russian Federation for the hack, Friday's indictment lays out for the first time the details of how it is believed to have been carried out by two Moscow-based GRU departments, Units 26165 and 74455.
The wreckage of what Robert Mueller's team says were Russian strikes on the U.S. can be measured in damaged reputations and disrupted politics. So while there were suspicions about Russian Federation, the precise motives behind the leaks were hard to divine. "Anything you do, it's always going to be, 'Oh, Russia, he loves Russia'".
■ They used a network of computers in the United States and other countries and paid for the infrastructure using the cryptocurrency bitcoin.More news: Angelique Kerber claims maiden Wimbledon triumph, Serena Williams denied fairy-tale comeback
The Associated Press contributed to this article.