A defiant President-elect Donald Trump on Wednesday adamantly denied reports that Russia had compromising personal and financial information about him, calling it a "tremendous blot" on the record of the intelligence community if material with any such allegations had been released.

The incoming president, in his first news conference since late July, firmly chided news organizations for publishing the material late Tuesday night. After weeks of scoffing at reports that Russians had interfered in the election, he conceded publicly for the first time that Russia was likely responsible for the hacking of the Democratic National Committee.

"As far as hacking, I think it was Russia," he said, and quickly added that the United States is hacked by other countries as well.

Trump's extraordinary defense against the unsubstantiated intelligence report, just nine days before his inauguration, dominated a highly anticipated press conference in which he also announced a new Cabinet member, detailed his plans to disentangle himself from his sprawling global business empire, gave his outlook on the future of the "Obamacare" health care law and said he would soon nominate someone to fill the vacancy on the Supreme Court.

"I think it's a disgrace that information would be let out. I saw the information, I read the information outside of that meeting," he said, a reference to a classified briefing he received from intelligence leaders. "It's all fake news, it's phony stuff, it didn't happen," Trump said in a news conference that saw him repeatedly joust with reporters. "It was gotten by opponents of ours."

Asked about his relationship with Russian President Vladimir Putin, Trump boasted that it is an improvement over what he called America's current "horrible relationship with Russia" and did not criticize the Russian leader for any interference in the election.

"If Putin likes Donald Trump, guess what, folks, that's called an asset not a liability. I don't know if I'm going to get along with Vladimir Putin - I hope I do - but there's a good chance I won't."

Trump, Vice-President-elect Mike Pence and incoming White House press secretary Sean Spicer also denounced the report about Russia's influence on Trump, and the incoming president said it never should have been released. He thanked some news organizations for showing restraint.

A US official told The Associated Press on Tuesday night that intelligence officials had informed Trump last week about an unsubstantiated report that Russia had compromising personal and financial information about him.

The official spoke on the condition of anonymity because the official was not allowed to publicly discuss the matter.