President-elect Donald Trump said, "Unless you catch 'hackers' in the act, it is very hard to determine who was doing the hacking"
Washington (AFP) - Leading senators supported a congressional investigation on Monday into US intelligence assessments that Russia interfered in the election, putting top Republicans on a collision course with incoming president Donald Trump.
The potential showdown between Trump and Capitol Hill could become more contentious after the president-elect announces his pick for the critical secretary of state post on Tuesday, with key Republicans concerned over his expected choice, ExxonMobil chief executive Rex Tillerson.
The president-elect has dismissed the intelligence reports about Russian interference as "ridiculous," defying an increasing number of senators from his own party, as well as top Democrats, the Central Intelligence Agency and the outgoing White House.
US media have reported for days on secret CIA findings that Moscow sought to bolster Trump's election bid, against Democratic former secretary of state Hillary Clinton, by releasing hacked Democratic Party documents.
A group of 10 electors who will ratify the election results next week -- all but one of them Democrats -- also called for a full briefing on the accusations before the 538-member Electoral College gathers on December 19.
"Can you imagine if the election results were the opposite and WE tried to play the Russia/CIA card. It would be called conspiracy theory!" Trump tweeted as he began another day of cabinet-building talks.
"Unless you catch 'hackers' in the act, it is very hard to determine who was doing the hacking. Why wasn't this brought up before election?"
After the Kremlin dismissed the US intelligence findings as "absolutely unfounded," a Trump transition spokesman dug in further, saying it was "an attempt to try to delegitimize president-elect Trump's win."
- 'No doubt' -
Republican Senators John McCain and Lindsey Graham, as well as Democrats Chuck Schumer and Jack Reed called for a bipartisan investigation with public hearings to find out what happened and to stop the threats that "cyberattacks conducted by foreign governments pose to our national security."
McCain told CBS television that there was "no doubt" about the hacking.
He said the investigation should stretch across armed services, intelligence and foreign relations committees in Congress to get a full picture of the story.
But Mitch McConnell, the powerful Senate majority leader whose wife Elaine Chao is Trump's nominee for transportation secretary, said the issue should be handled by the Senate Intelligence Committee, whose leader Richard Burr has been silent on the issue since the reports first appeared on Friday.
"It's an important subject and we intend to review it on a bipartisan basis," McConnell told CNN.
Republican Senator Michael McCaul, chairman of the Homeland Security Committee, said it must be "a top priority to investigate any outside interference aimed at undermining our democratic process."
The White House has also backed a congressional review.
Trump has long fanned alarm among some Republicans for calling for closer ties with Moscow, perhaps at their worst since the end of the Cold War, in contrast to received wisdom in Washington that Russia remains a global security threat.
- Tillerson questions -
American intelligence previously linked Russia to damaging email leaks from the Clinton campaign, but saw it as a broad bid to undermine confidence in the US political process.
On Friday, however, The Washington Post reported that the CIA has since concluded that the aim of the cyber intrusions was to help Trump win.
The report came on the heels of President Barack Obama's order to review all cyberattacks that took place during the 2016 election cycle, amid growing calls from Congress for more information on the extent of Russian interference.
Trump's rejection of the CIA conclusions signals a likely rough start to relations with the spy agency when the president-elect takes office on January 20.
"He believes that the CIA is a political institution and he's going to have to learn that it's not. It is apolitical," former deputy CIA director Michael Morell told CBS.
The hacking scandal raised new questions about whether Trump's apparent favored choice for US secretary of state will be able to pass Senate confirmation.
Tillerson's extensive dealings on behalf of Exxon with Russian leader Vladimir Putin have raised conflict of interest questions.
Putin bestowed Russia's Order of Friendship on Tillerson.
Republican Senator Marco Rubio, a member of the Senate Foreign Affairs Committee which must approve the nomination, tweeted: "Being a 'friend of Vladimir' is not an attribute I am hoping for from a #SecretaryOfState."
Separately, Trump is delaying a press conference originally planned for Thursday about his global business dealings until January, top advisor Kellyanne Conway told CNN, as critics point to a myriad of potential conflicts of interest.
She attributed the delay to "how convoluted and complex many of these business holdings are," adding that Trump still intends to relinquish operational control of his company while serving as president.
"He's just a man who's been incredibly successful and has holdings all across the globe."