US President Barack Obama says the United States will respond to Russian cyber attacks that the intelligence community concluded were part of an effort to influence the US presidential election.
US intelligence officials said hackers working for Russia hacked into the emails of the Democratic Party and a key Hillary Clinton aide.
The intelligence agencies said they had overwhelming evidence Russian hackers linked to the Kremlin were behind the hacks.
On Thursday, a White House spokesman said President Vladimir Putin was involved.
The Kremlin denies the allegations.
Republican president-elect Donald Trump has dismissed the claim as "ridiculous" and politically motivated.
Mr Obama told National Public Radio: "I think there's no doubt that when any foreign government tries to impact on the integrity of our elections, that we need to take action and we will, at a time and a place of our own choosing.
"Some of it may be explicit and publicised. Some of it may not be.
"Mr Putin is well aware of my feelings about this, because I spoke to him directly about it," Mr Obama said.