The White House has suggested Russian President Vladimir Putin was directly involved in a hacking operation aimed at interfering with the US election.
Ben Rhodes, adviser to President Barack Obama, said that Mr Putin maintains tight control on government operations, which suggests that he was aware.
White House Press Secretary Josh Earnest added that it was "pretty obvious" that Mr Putin was involved.
Officials in Russia have repeatedly denied hacking accusations.
"Everything we know about how Russia operates and how Putin controls that government would suggest that, again, when you're talking about a significant cyber intrusion like this, we're talking about the highest levels of government," Mr Rhodes said.
"And ultimately, Vladimir Putin is the official responsible for the actions of the Russian government."
The Kremlin on Thursday bristled at claims that Mr Putin orchestrated the data breach with the hopes of influencing the US election outcome.