WASHINGTON • President Barack Obama said the United States would retaliate for Russia's efforts to influence the presidential election, asserting that "we need to take action", and "we will".
The comments, in an interview with National Public Radio (NPR), indicate that Mr Obama, in his remaining weeks in office, will pursue either economic sanctions against Russia or perhaps some kind of response in cyberspace.
The outgoing US President's remarks on Thursday dramatically upped the stakes in a dispute between the world's leading nuclear powers over interference that may have swayed last month's tight election in which President-elect Donald Trump defeated Democrat Hillary Clinton.
"I think there is no doubt that when any foreign government tries to impact the integrity of our elections... we need to take action," Mr Obama told NPR radio.
A secret Central Intelligence Agency (CIA) assessment found that Russia sought to tip the election in Mr Trump's favour, The Washington Post reported last week.
The paper cited officials briefed on the matter as saying that individuals with connections to Moscow provided anti-secrecy website WikiLeaks with e-mails hacked from the Democratic National Committee, Mrs Clinton's campaign chief and others.
WikiLeaks founder Julian Assange has denied links with Russia's government.
The Kremlin yesterday criticised the allegations and said the US government should provide proof.
"At this point, they need to either stop talking about this or finally present some sort of proof. Otherwise, this looks extremely scurrilous," Russian President Vladimir Putin's spokesman Dmitry Peskov told journalists during a Japan visit.
Mr Trump again refused to accept Moscow's culpability, asking on Twitter why the administration had waited "so long to act" if Russia "or some other entity" had carried out cyber attacks.
The White House strongly suggested before the election that Mr Obama would make use of sanctions authority for cyber attacks that he had given to himself by executive order. But he did not, in part out of concern that action before the election could lead to an escalated conflict.
If Mr Obama invokes sanctions on Russian individuals or organisations, Mr Trump could reverse them. But that would be politically difficult, as his critics argue that he is blind to Russian behaviour.
On Thursday, pressure grew on Mr Trump in Congress for him to acknowledge intelligence agen- cies' conclusions that Russia was behind the hacking. But aides said that was all but impossible before the Electoral College convenes on Monday to formalise his victory.
In his posting on Thursday, Mr Trump falsely stated that Mr Obama had waited until after the election to raise the issue. "Why did they only complain after Hillary lost?" he asked, although director of national intelligence James Clapper formally blamed Russia on Oct 7 for cyber attacks on the Democratic National Committee.
In September, meeting privately in China with Mr Putin, Mr Obama not only complained, the White House says, but also warned him of consequences if the Russian activity did not stop.
Among those in his own party, Mr Trump's refusal to accept the evidence that Russia was the perpetrator was raising growing concerns, with Senator Lindsey Graham of South Carolina saying he would not vote for Mr Rex Tillerson, Mr Trump's nominee for secretary of state, unless Mr Tillerson addressed Russia's role during his confirmation hearings.
NYTIMES, AGENCE FRANCE-PRESSE
SEE WORLD
OPINION
An oath to ensure a truthful election
The new reality of TV: All Trump, all the time
