Russia has tried to affect the US congressional elections in November online, states Daniel Coats, the head of the American intelligence services (DNI).
China and Iran have also conducted influencing campaigns aimed at the United States.
The head of the sixteen American intelligence services sent a report on Friday with his findings to US President Donald Trump. Trump signed a decree in September so that the DNI must report on possible foreign interference within 45 days of an election.
The report does not address whether the influencing campaign changed the outcome of an election. That is a task for the US Ministries of Justice and Homeland Security, which will come up with their findings within a month and a half.
Facebook announced in the run-up to the congressional elections that they had removed dozens of pages and accounts on Facebook and Instagram. The company, which manages both social media, has been under a magnifying glass since the presidential elections because it would be used to conduct the influencing campaign.