President Barack Obama's order to intelligence officials for a full-scale review of campaign-season cyberattacks has prompted President-elect Donald Trump's transition team to say it is "time to move on".
Trump's transition office issued a statement on Saturday criticising the Central Intelligence Agency officials for revealing that Russia had aimed specifically to help Trump win the presidency.
"These are the same people that said Saddam Hussein had weapons of mass destruction," the statement said.
OPINION: The Kremlin and the US election
"The election ended a long time ago in one of the biggest Electoral College victories in history. It's now time to move on and 'Make America Great Again'."
Trump has been repeatedly dismissive of the intelligence community's determination that Russia sought through hacking to disrupt the US election, and Obama's new initiative was similarly brushed off by the Trump transition team.
The investigation ordered by Obama will be a "deep dive" into a possible pattern of increased "malicious cyber activity" timed to the campaign season, Eric Schultz, White House spokesman, said on Friday.
Schultz said it will look at the tactics, targets, key actors and the US government's response to the recent email hacks, as well as incidents reported in past elections.
The president ordered the report earlier in the week and asked that it be completed before he leaves office next month, Schultz said.
Russia has rejected the hacking accusations.
In the months leading up to the election, email accounts of Democratic Party officials and a top Hillary Clinton campaign aide were breached, emails leaked and embarrassing and private emails posted online.
Many Democrats believe the hackings benefited Trump's bid.
Schultz said the president sought the probe as a way of improving US defence against cyberattacks and was not intending to question the legitimacy of Trump's victory.
"This is not an effort to challenge the outcome of the election," Schultz said.
Obama's move comes as Democratic politicians have been pushing Obama to declassify more information about Russia's role, fearing that Trump, who has promised a warmer relationship with Russia, may not prioritise the issue.
Source: News agencies