US vice president Joe Biden has said top intelligence leaders told him and President Barack Obama about unsubstantiated claims about Donald Trump because they were concerned the information might become public.

Mr Biden said he and Mr Obama were initially surprised that intelligence officials felt the need to brief them on unverified claims that Russia had compromising information about President-elect Trump.

The vice president said: "It's something that obviously the agency thinks they have to track down."

Mr Biden did not specify which agency, but said later that he was surprised the allegations "made it to the point where the agency, the FBI thought they had to pursue it".

The vice president said neither he nor Mr Obama asked for more details.

He said the intelligence community could not say whether the information was true.

Mr Biden was also sharply critical of Mr Trump for publicly disparaging intelligence officials, saying the incoming president is damaging America's standing in the world and playing into Russia's hands

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

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

He said that in the briefing he and Mr 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.

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

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

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

Mr Trump has vehemently denied the allegations included in the dossier.

The dossier was compiled by a former Western intelligence operative and had been circulating among news organisations and intelligence agencies in Washington for months. Its existence became known publicly following reports the intelligence community had briefed Mr Trump on it.

In the interview, Mr Biden also criticised Mr Trump's rocky relationship with intelligence officials. The president-elect has publicly challenged their assessment about Russia's role in the election and suggested they have skewed evidence.

Mr Trump has received intelligence briefings but has insisted he does not need a daily update, and has suggested he knows more than intelligence leaders.

Mr Biden said it would be a "genuine tragedy" if he refuses the daily intelligence briefing presidents traditionally receive, and he said at least five foreign leaders have already contacted him expressing concern over Mr Trump's second-guessing of US intelligence agencies.

"It is really very damaging, in my view, to our standing in the world for a president to take one of the crown jewels of our national defence and denigrate it," Mr Biden said.

"It plays into, particularly now, the Russian narrative that America doesn't know what it's doing."