Amid calls on both sides of the political aisle on Capitol Hill for a full-bore congressional investigation, including assertions President Vladimir Putin was personally involved, Obama said that anytime a foreign government tries to interfere in US elections, the nation must take action "at a time and place of our own choosing — and we will."
"Some of it may be explicit and publicized, some of it may not be," he said, the Associated Press reported on Friday.
"But Mr. Putin is well aware of my feelings about this, because I spoke to him directly about it."
White House officials said it was "fact" that Russian hacking helped Donald Trump's campaign against Democratic presidential nominee Hillary Clinton. Administration officials on Thursday also assailed Trump himself, saying he must have known of Russia's interference. Obama was to hold a news conference at the White House on Friday afternoon.
No proof was offered for any of the accusations, the latest to unsettle America's uneasy transition from eight years under Obama to a new Republican administration led by Trump. The claims of Russian meddling in the election also have heightened already debilitating tensions between Washington and Moscow over Syria, Ukraine and a host of other disagreements.
The Kremlin rejected the claim of Putin's involvement, with Putin spokesman Dmitry Peskov dismissing it as "laughable nonsense."
There has been no specific, persuasive evidence shared publicly about the extent of Putin's role or knowledge of the hackings. That lack of proof undercuts Democrats' strategy to portray Putin's involvement as irrefutable evidence of a directed Russian government plot to undermine America's democratic system.
The dispute over Russia's role is fueling an increasingly public spat between Obama's White House and Trump's team that is threatening to spoil the delicate truce that Obama and Trump have forged since Election Day to smooth the billionaire businessman's move to the White House in little over a month.