By Tal Kopan, CNN

(CNN) -- Homeland Security Secretary Kirstjen Nielsen on Wednesday called out Russian President Vladimir Putin by name for interfering in the 2016 US election, calling it a "direct attack" on US democracy.

"At Vladimir Putin's direction, Moscow launched a brazen, multi-faceted influence campaign to undermine public faith in our democratic process and to distort our presidential election," Nielsen said at George Washington University in Washington. "Although no actual ballots were altered by this campaign, make no mistake: This was a direct attack on our democracy."

Nielsen continued that the administration "will not tolerate" such interference nor "let it happen again."

Nielsen has spoken out repeatedly on election interference but has faltered when asked directly whether the interference was designed to help President Donald Trump get elected. Nielsen has said she "agree(s) with the intel community's assessment, full stop," an assessment that concluded the interference was done with the intention of bolstering Trump and harming his opponent, Hillary Clinton, politically.

But at the Aspen Security Forum in July, she said, "I haven't seen any evidence that the attempts to interfere in our election infrastructure was to favor a particular political party."

Trump himself has repeatedly wavered on Russian interference, at times reading statements that he blames Russia for the interference, but then returning to casting doubt on the intelligence findings, including referring often to a "Russian hoax."

Nielsen said her agency is working with others to counteract the threat, including by trying to address propaganda-like influence campaigns on social media and the Internet.

"We're not trying to stop freedom of speech, but we do have a belief in this country that we want to know or at least have a sense of knowing who is saying what and if we're being manipulated," she said.

Nielsen also indicated there would be consequences for cybermeddling, though she did not get into specifics. She noted responses including "some seen, others unseen."

"We will no longer naively assume that a nation state with cyber capabilities chooses not to use them," Nielsen said. "We will respond. And we will respond decisively. ... The days of cybersurrender are over. And this administration is replacing complacency with consequences, replacing nations' deniability with accountability."

DHS has also been working with states that accept their help to test cyberdefences. She encouraged all states to have voting systems by 2020 that can be audited, preferably by a paper trail.