President-elect Donald Trump on Wednesday berated the media and U.S. intelligence agencies as he denied explosive allegations about his ties with Russia -- while admitting for the first time that Moscow had likely meddled in the U.S. election.

Just over a week before he takes office, Trump confirmed he had ceded "complete" managing control of his global property empire to his two sons, seeking to dispel fears about possible conflict of interests.

But the focus of the hour-long press conference -- his first in six months -- was firmly on the unsubstantiated claims that his aides colluded with the Kremlin to win the U.S. election, and that Russia has compromising information on Trump.

The 70-year-old billionaire angrily accused CNN of being "fake news" and called BuzzFeed -- which published a dossier with the allegedly incriminating material drawn up by a former British intelligence agent hired to do "opposition research" on Trump -- a "failing pile of garbage."

"It's all fake news. It's phony stuff. It didn't happen," he said, referring to allegations of lurid behavior in a Moscow hotel room.

"It was a group of opponents that got together, sick people, and they put that crap together," Trump said.

"I think it's a disgrace that information would be let out," Trump said.

It "was released by maybe the intelligence agencies, who knows, but maybe the intelligence agencies, which would be a tremendous blot on their record," Trump said, later saying it was "disgraceful."

On Twitter, he earlier decried a political "witch hunt" against him and asked: "Are we living in Nazi Germany?"

- Verbal clash with reporters -

Trump dodged specific questions about whether his campaign had contacts with Russian intelligence, instead tearing into reporters whose outlets reported the suggestions of compromising material.

"I'm not going to give you a question. You are fake news," he said to a CNN reporter, igniting a fresh raft of questions about his respect for constitutional guarantees about the free press.

Trump warned BuzzFeed they would "suffer the consequences."

The U.S. intelligence community has already concluded Moscow interfered in the November election in a bid to tip the race in Trump's favor.

But intelligence chiefs last week presented America's incoming 45th president, as well as current President Barack Obama, with a two-page synopsis on the potentially embarrassing but unsubstantiated allegations involving Russia, according to CNN and The New York Times.

Even before the new allegations surfaced, Trump's Republican allies had become increasingly uneasy about Russia's role in the election, with calls for an independent investigation growing.

The Kremlin has dismissed the dossier as a "total fake" aimed at damaging bilateral ties.

- 'No dealings with Russia' -

Trump began the press conference muted and disciplined, but became increasingly agitated as questions piled up.

"I have no dealings with Russia. I have no deals in Russia. I have no deals that could happen in Russia, because we've stayed away. And I have no loans with Russia," Trump said.

The president-elect finally admitted for the first time that he believes Moscow likely meddled in the U.S. election. U.S. intelligence agencies say Russia's intent was to help Trump win the White House.

But with Congress pressing many of his cabinet nominees on their stance toward Russia -- including secretary of state-designate Rex Tillerson, whose hearing opened Wednesday -- Trump may have fanned the flames by again downplaying its role.

"As far as hacking, I think it was Russia, but I also think we've been hacked by other countries, other people," he said.

Trump aides bristle at the suggestion that Russia weighed in behind Trump, seeing it as an effort to delegitimize his election victory.

Trump again refused to back away from his openness towards Russian President Vladimir Putin.

"If Putin likes Donald Trump, I consider that an asset, not a liability, because we have a horrible relationship with Russia," Trump said.

"I don't know that I'm going to get along with Vladimir Putin. I hope I do. But there's a good chance I won't."

- The dossier -

Without corroborating its contents, BuzzFeed published a 35-page dossier of memos on which the synopsis reportedly presented to Trump is based.

The memos, which had been circulating in Washington for months, describe sex videos involving prostitutes filmed during a 2013 visit by Trump to a luxury Moscow hotel, supposedly as a potential means for blackmail.

They also suggest Russian officials proposed lucrative deals in order to win influence over the real estate magnate.

"The Kremlin does not have compromising information on Trump," Russian President Vladimir Putin's spokesman Dmitry Peskov telling journalists.

The Kremlin spokesman called the dossier a "total fake" and "an obvious attempt to harm our bilateral relations."

Trump refused to comment on his classified briefing but said he had seen the information "outside of that meeting."

Without delineating the specific allegations in the memos, Trump denied engaging in any questionable behavior during visits to Russia.

"In those rooms, you have cameras in the strangest places -- cameras that are so small, with modern technology. You can't see them and you won't know," he said.

"You'd better be careful or you'll be watching yourself on nightly television."

As for the rise of the Islamic State terrorist group, Trump said: "This administration created ISIS by leaving (the Middle East) at the wrong time."