America's director of national intelligence has spoken to Donald Trump about the unsubstantiated report claiming Russia had compromising personal and financial information about the president-elect.
In a statement, James Clapper said he told Mr Trump the intelligence community "has not made any judgment that the information in this document is reliable".
Mr Clapper also said he told Mr Trump he did not believe any leaks from Friday's meeting between the president-elect and intelligence officials came from the intelligence community.
The dossier contains unproven information about close co-ordination between Mr Trump's inner circle and Russians about hacking into Democrat Party accounts as well as unproven claims about unusual sexual activities by Mr Trump, among other suggestions attributed to anonymous sources.
None of the claims has been authenticated.
Mr Clapper's statement came after Mr Trump said for the first time that he accepted Russia was behind the election-year hacking of Democrats that rocked the White House race.
But during an hour-long news conference in the marbled lobby of his Manhattan skyscraper, Mr Trump strongly denied reports that Russia had collected the compromising personal and financial information about him, lambasting the media for peddling "fake news" and shouting down a journalist from CNN, which reported on the matter.
Mr Trump's transition has been shadowed by US intelligence assessments that Russia not only meddled in the election, but did so to help him defeat Democrat Hillary Clinton.
After spending weeks challenging that idea, the president-elect finally accepted at least part of the intelligence conclusions.
"As far as hacking, I think it was Russia," Mr Trump said, quickly adding that "other countries and other people" also hack US interests.
But he continued to needle the intelligence agencies, saying it would be a "tremendous blot" on their record if officials were leaking information from his classified briefings.