Although the Trump campaign and private-sector cybersecurity investigators had previously said Iran was behind the hacking attempts, it was the first time the U.S. government had assigned blame for the attack.

The joint statement from the FBI and other federal agencies also indicated that Iran was responsible for attempts to hack Vice President Kamala Harris' campaign, saying hackers had "sought access to individuals with direct access to the Presidential campaign of both political parties."

The goal of the hacking and other activities, federal officials said, was not only to sow discord but also to shape the outcome of elections that Iran perceives to be "particularly consequential in terms of the impact they could have on its national security interests."

"We have observed increasingly aggressive Iranian activity during this election cycle, specifically involving influence operations targeting the American public and cyber operations targeting Presidential campaigns," said the statement, which in addition to the FBI was also released by the Office of the Director of National Intelligence and the Cybersecurity and Infrastructure Security Agency.

The statement largely confirms the findings of private companies like Microsoft, which earlier this month issued a report detailing foreign agents' attempts to interfere in this year's election, and Google, which separately said that an Iranian group linked to the country's Revolutionary Guard has tried to infiltrate the personal email accounts of roughly a dozen people linked to President Joe Biden and Trump since May.