The US Department of Homeland Security and US Department of Justice released a statement on Tuesday, said the US government has found no evidence that foreign governments or agents had an impact last November, when Democrats won control of the House of Representatives, the lower chamber of Congress.
Neither election campaigns nor electronic voting machines or other infrastructure was significantly affected, they said in their joint statement
The statement stands in contrast to the 2016 US presidential election, which American officials say was the target of a sophisticated Russian hacking and propaganda campaign, Presstv reported.
The National Republican Congressional Committee, which works to elect Republican candidates, said it was the target of a hacking attempt last year.
US federal investigators are probing whether President Donald Trump’s election campaign colluded with Moscow to win the 2016 election.
Trump denies any collusion, and Moscow has also denied involvement.
US intelligence officials warned last week that Russia and China are already targeting the 2020 presidential election.
After winning the 2016 election through electoral votes and despite losing the popular vote, Trump formed a voter fraud committee, accusing Democrats of getting undocumented immigrants to vote in favor of his rival, Democratic nominee Hillary Clinton.
A new study shows that democracy in the United States has experienced a significant decline under Trump, who keeps attacking people's democratic freedoms on a regular basis.
Freedom House, a US-based non-governmental group, warned in its latest report on Monday that US democratic freedoms were eroding at rates similar to countries where democracy had been ultimately overtaken by authoritarianism.