"I do not believe that I’ve seen that conclusion that the specific intent was to help President Trump win," Nielsen said after a briefing on Capitol Hill. "I’m not aware of that."
However, Nielsen also said she had no reason to question any intelligence findings and added that Russia did try to influence US voters and will continue to do it in the future.
Office of Special Counsel Robert Mueller has been investigating allegations of Trump campaign collusion with Russia for more than a year.
Trump has characterized the probe as a "witch hunt" and urged Mueller to wrap up the investigation as it has dragged without finding evidence of collusion.
In January 2017, the US intelligence community issued an assessment in which it concluded that Russia tried to help Trump win the presidential election by launching a campaign against his Democratic rival Hillary Clinton.