WASHINGTON -- Vice President Joe Biden said Thursday top intelligence leaders told him and President Barack Obama they felt obligated to inform them about uncorroborated allegations about President-elect Donald Trump out of concern the information would become public and catch them off-guard.

In an interview, Biden said neither he nor Obama asked U.S. intelligence agencies to try to corroborate the unverified claims Russia had obtained compromising sexual and financial allegations about Trump.

"I think it's something that obviously the agency thinks they have to track down," Biden said. He added later, "It surprised me in that it made it to the point where the agency, the FBI thought they had to pursue it."

In the hourlong session with The Associated Press and other news outlets, the vice president was sharply critical of Trump for publicly disparaging intelligence officials, saying Trump was damaging U.S. standing and playing into Russia's hands.

He also took umbrage at Trump's comments accusing intelligence agencies of allowing the information to leak publicly and drawing a comparison to "living in Nazi Germany."

"The one thing you never want to invoke is Nazi Germany, no matter what the circumstances," Biden said. "It's an overwhelming diversion from the point you're trying to make."

Biden said in the briefing he and Obama received from director of national intelligence James Clapper and others, there were "no conclusions drawn" from the uncorroborated dossier, which was produced in August and then released publicly this week by the media.

Biden said it was "totally ancillary" to the purpose of the meeting, which was to brief Obama on a report he ordered documenting Russian interference in the U.S. campaign.

"As a matter of fact, the president was like, 'What does this have anything to do with anything?'" Biden said.

He said intelligence leaders responded by saying, "Well, we feel obliged to tell you, Mr. President, because you may hear about it. We're going to tell him," referring to Trump.

Biden said intelligence leaders told him and Obama they couldn't say whether the allegations were true or untrue. He said there was "hardly any discussion" about the allegations in the briefing.

"Neither the president nor I asked for any detail," Biden said. But he added of the dossier: "I've read everything."

Trump has vehemently denied the allegations included in a dossier about close coordination between his inner circle and Russians. The dossier also included unsubstantiated claims about unusual sexual activities by Trump, attributed to anonymous sources.

The Associated Press has not authenticated the claims. Trump has denied them.

The FBI has been working to corroborate the details in the dossier, although it's unclear how long that investigation has been running or how many resources are assigned.

FBI director James Comey has declined even to acknowledge the investigation publicly in line with FBI protocol.

The dossier was compiled by a former Western intelligence operative and had been circulating among news organizations and intelligence agencies in Washington for months.