The White House on Thursday pointed to Russian President Vladimir Putin's direct involvement in cyber attacks designed to impact the US election, dramatically upping the stakes in a conflict between the world's two leading nuclear powers.

"I don't think things happen in the Russian government of this consequence without Vladimir Putin knowing about it," Ben Rhodes, a top advisor to President Barack Obama, told MSNBC television.

"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," he said.

"And ultimately, Vladimir Putin is the official responsible for the actions of the Russian government."