"I haven't seen a significant decrease in their activity," Pompeo told the BBC of the Russians.
"I have every expectation that they will continue to try and do that, but I'm confident that America will be able to have a free and fair election (and) that we will push back in a way that is sufficiently robust that the impact they have on our election won't be great," he said.
The leading US intelligence agencies concluded at the end of 2016 that Russian President Vladimir Putin had directed a broad intelligence effort to influence the presidential election that year to undermine the campaign of Democrat Hillary Clinton and boost Donald Trump's chances.
That effort included hacking and releasing emails and documents from the Clinton campaign and filling social media with posts and "news" items aimed at discrediting her.
Trump has repeatedly dismissed the idea that Moscow helped him -- and allegations his campaign colluded with the Russians -- as fake news.
The 2018 midterm elections will involve all of the 435 members of the House of Representatives and 33 senators.
In the elections, minority Democrats will be battling to try and prise control of the two houses from Trump's Republicans.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)