President-elect Donald Trump rejected as "ridiculous" reported U.S. intelligence findings that Russia intervened in the presidential election on his behalf through targeted hacking, according to an interview broadcast on Sunday.

"I think it's ridiculous. I think it's just another excuse. I don't believe it," Trump said in the interview with "Fox News Sunday."

The Republican president-elect's comments casting doubt on reported U.S. intelligence findings pits him against some leading foreign policy voices in the U.S. Senate from his own party who on Sunday expressed alarm about election meddling by Moscow and called for a bipartisan investigation.

He blamed Democrats for putting out the media reports and said he did not believe they came from the Central Intelligence Agency.

Trump's dismissal was perhaps aimed at squashing doubts about whether he won the Nov. 8 election fairly. However, his comments could also portend conflicts between the new president and the intelligence agencies he will command and feed criticism that his administration will be soft on Russia.

In his search for a secretary of state nominee, the Republican real estate magnate is strongly considering Exxon Mobil Corp Chief Executive Rex Tillerson, who has close ties with Moscow and has spoken out against U.S. sanctions on Russia.

"It's a matter of concern to me that he has such a close personal relationship with Vladimir Putin and obviously they’ve done enormous deals together," Republican U.S. Senator John McCain said on CBS' "Face the Nation" program. "That would color his approach to Vladimir Putin and the Russian threat."

U.S. intelligence agencies have told Congress and the administration of President Barack Obama that Russia has grown increasingly aggressive in Syria and Ukraine and has stepped up activities in cyberspace including meddling, sometimes covertly, in European and U.S. elections.

A senior U.S. intelligence official told Reuters intelligence agencies have concluded with "high confidence" that not only did their Russian counterparts direct the hacking of Democratic Party organizations and leaders, but they did so to undermine Democratic candidate Hillary Clinton.

Russian officials have denied all accusations of interference in the U.S. election.

CONGRESS TO INVESTIGATE

Trump questioned whether the CIA was behind the reports that indicated Moscow wanted him in the White House. "I think the Democrats are putting it out," he said in the interview.

McCain said on Sunday he was at a loss to explain Trump's repudiation of the reports.

"I don’t know what to make of it because it's clear the Russians interfered," McCain said on CBS.

"Whether they intended to interfere to the degree that they were trying to elect a certain candidate, I think that’s a subject of investigation, but the facts are stubborn things."

McCain and fellow Republican Senator Lindsey Graham joined Democratic Senators Chuck Schumer and Jack Reed on Sunday in expressing concern over possible Russian interference in a U.S. presidential election and said they will work together to investigate such cyber attacks.

"Recent reports of Russian interference in our election should alarm every American," they said in the statement. "This cannot become a partisan issue. The stakes are too high for our country."

McCain, chairman of the Armed Services Committee, said he would have a subcommittee led by Graham begin investigating the Russian hacking immediately.

Trump advisers disputed elements of the news reports, focusing particularly on a New York Times story saying that intelligence officials concluded the computer systems of the Republican National Committee also had been hacked. The fact that material from that intrusion had not been released, the Times reported, supported the conclusion that Russia was trying to help Trump.

"The RNC was absolutely not hacked,” incoming White House chief of staff Reince Priebus said on NBC's "Meet the Press."

Trump adviser Kellyanne Conway said Trump would not interfere with any congressional inquiry, but also said the president-elect regarded the spate of hacking reports as part of an effort to relitigate the election.

"He absolutely respects the intelligence community," Conway said on CBS. "What he has said is laughable or ridiculous is that this was meant to elevate him to the presidency."

(This story was refiled to fix typo in name of Exxon Mobil Corp instead of Mobile in sixth paragraph)

(Additional reporting by Lindsay Dunsmuir; Editing by Mary Milliken and Phil Berlowitz)