"This assertion has absolutely nothing to do with reality," he said on a conference call with reporters, Reuters reported.
"We have heard no arguments proving the veracity of this information ... Therefore we strongly deny the very possibility that this could have happened."
A report Monday, citing a National Security Agency investigation report, said Russian intelligence agents hacked a U.S. voting systems manufacturer in the weeks leading up to the 2016 presidential election.
The Intercept reported Monday that the NSA believes hackers used that breach to obtain information used to spearphish its customers.
The report, marked top secret and only to be shared with the "Five Eyes" nations (Canada, Britain, New Zealand and Australia), claims the Russian intelligence agency GRU targeted more than 120 email addresses associated with local government organizations, which it speculates were taken from the earlier hack.
A government contractor was charged Monday by the Justice Department with leaking classified information to a media outlet.