The Republican said leaks from the intelligence community led to some U.S. media outlets reporting unsubstantiated claims that he was caught in a compromising position in Russia.
"I think it was disgraceful, disgraceful that the intelligence agencies allowed any information that turned out to be so false and fake out. I think it's a disgrace, and I say that ... that's something that Nazi Germany would have done and did do," Trump told a news conference in New York.
For the first time, Trump acknowledged that Russia likely hacked the Democratic National Committee and the emails of top Democrats during the 2016 presidential election. "I think it was Russia,” he said, pointing out that other countries were also hacking the United States.
Trump’s comments about spy agencies such as the CIA are likely to intensify tensions between the intelligence community and the president-elect, who initially disparaged its conclusion that a Russian hacking campaign was aimed at boosting his candidacy against Democrat Hillary Clinton.
Trump, who takes office on Jan. 20, called a dossier that makes salacious claims about him in Russia "fake news" and "phony stuff."
MEMO AND REPORTS
Two U.S. officials said the allegations about Trump, which one called "unsubstantiated," were contained in a two-page memo appended to a report on Russian interference in the 2016 election that was presented last week to Trump and to President Barack Obama.
Trump said, without offering evidence, that the news he had been briefed on the memo "was released by maybe the (U.S.) intelligence agencies. Who knows? But maybe the intelligence agencies which would be a tremendous blot on their record if they in fact did that."
CNN reported on Tuesday about the existence of the memo. BuzzFeed published a fuller 35-page document produced by Christopher Steele, a former British foreign intelligence official, that outlined the allegations of compromising behavior by Trump and alleged links between the businessman and people in Russia.
The claims were included in opposition research reports that were made available last year to Democrats and U.S. officials.
One U.S. official said investigators had so far been unable to confirm material about Trump's financial and personal entanglements with Russian businessmen and others whom U.S. intelligence analysts have concluded are Russian intelligence officers or working on behalf of Russian intelligence.
Some material in Steele's reports has proved to be erroneous, the U.S. official said.
In the news conference, Trump declined to answer whether anyone connected to him or the campaign had contact with Moscow during the presidential campaign, and said he had no loans or business deals with Russia.
He defended his goal of better ties with Russian President Vladimir Putin. "If Putin likes Donald Trump, I consider that an asset, not a liability," he said.
The New York real estate developer complained about leaks from meetings he has with intelligence agencies and suggested they were to blame.
"I have many meetings with intelligence. And every time I meet, people are reading about it. Somebody's leaking it out," he said.
PROTESTERS OUTSIDE, CHEERING AIDES INSIDE
The long-awaited news conference was a freewheeling affair, with Trump aides cheering from the sidelines at one point and the president-elect angrily refusing to take questions from a CNN reporter.
Outside, about a dozen protesters gathered behind a police barricade across the street from Trump Tower, holding signs with the slogans "Dump Trump" and "Allegiance To America Not Russia" as Fifth Avenue traffic streamed by.
It was Trump's first news conference in about six months. About 250 reporters jammed into the lobby at his Manhattan offices where Trump also slammed drug company pricing policies.
Questions extended to many issues that will face him when he takes office. He vowed to soon begin negotiations with Mexico on building a border wall and said he will nominate a Supreme Court justice to fill the seat left by the death of conservative Antonin Scalia within two weeks of taking office.
He also said he would offer a plan to repeal and replace Obama’s signature health care law once his choice for health and human services, Tom Price, is confirmed by the Senate.
Trump gestured to large stacks of manila folders as he described how he will separate himself from his global business operations, which includes hotels and golf courses as well as assets like a winery and modeling agency, to avoid conflicts of interest once he takes office.
He also talked about how he plans to bring manufacturing jobs back from overseas plants, slamming drug companies for "getting away with murder" on pricing.
U.S. stocks slipped to session lows, before recovering ground, as healthcare stocks took a beating following Trump's comments on drug pricing.