WASHINGTON — The Biden administration revealed on Thursday {that a} enterprise affiliate of Trump marketing campaign officers in 2016 supplied marketing campaign polling information to Russian intelligence providers, the strongest proof up to now that Russian spies had penetrated the interior workings of the Trump marketing campaign.

The revelation, made public in a Treasury Department document asserting new sanctions towards Russia, established for the primary time that non-public conferences and communications between the marketing campaign officers, Paul Manafort and Rick Gates, and their enterprise affiliate had been a direct pipeline from the marketing campaign to Russian spies at a time when the Kremlin was engaged in a covert effort to sabotage the 2016 presidential election.

Earlier authorities investigations have recognized the Trump aides’ affiliate, Konstantin V. Kilimnik, as a Russian intelligence operative, and Mr. Manafort’s determination to supply him with inner polling information was one of many mysteries that the particular counsel, Robert S. Mueller III, sought to unravel throughout his two-year investigation into Russia’s election meddling.

“Through the 2016 U.S. presidential election marketing campaign, Kilimnik supplied the Russian Intelligence Companies with delicate data on polling and marketing campaign technique,” the Treasury Division stated in a information launch. “Moreover, Kilimnik sought to advertise the narrative that Ukraine, not Russia, had interfered within the 2016 U.S. presidential election.”

The Biden administration supplied no supporting proof to bolster the evaluation that the Russian intelligence providers obtained the polling information and marketing campaign data. And the discharge shed no gentle on why Mr. Manafort and Mr. Gates gave polling information to Mr. Kilimnik, though earlier authorities stories have indicated that Mr. Manafort thought Trump marketing campaign technique data could possibly be a precious commodity for future enterprise offers with Kremlin-connected oligarchs.

Having the polling information would have allowed Russia to higher perceive the Trump marketing campaign technique — together with the place the marketing campaign was focusing assets — at a time when the Russian authorities was finishing up its personal efforts to undermine Donald J. Trump’s opponent.

The new sanctions against Russia are in response to the Kremlin’s election interference, efforts to hack American authorities companies and corporations, and different acts of aggression towards america.

The sanctions now make it extraordinarily tough for Mr. Kilimnik, who was indicted by the Justice Division in 2018 on costs of obstruction of justice, to have interaction in monetary transactions that will contain america.

It’s unclear how lengthy American spy companies have held the conclusion about Mr. Kilimnik. Senior Trump administration officers, fearing Mr. Trump’s wrath, repeatedly tried hold from the general public any data that appeared to indicate Mr. Trump’s affinity for Russia or its president, Vladimir V. Putin.

Mr. Kilimnik had been a longtime enterprise companion throughout Mr. Manafort’s time as a political guide in Ukraine. In 2018, prosecutors for Mr. Mueller’s workplace introduced that Mr. Kilimnik had “ties to Russian intelligence” and that Mr. Manafort had instructed Mr. Gates to move the polling and marketing campaign data to Mr. Kilimnik.

The Senate Intelligence Committee went additional final August in its bipartisan report that scrutinized the links between the Trump campaign and Russia — calling Mr. Kilimnik a “Russian intelligence officer.”

The report contained a number of important redactions that appeared associated to Mr. Manafort and Mr. Kilimnik however stated that Mr. Manafort’s willingness to share the knowledge with him “represented a grave counterintelligence menace.”

The report known as the relationship between Mr. Manafort and Mr. Kilimnik “the one most direct tie between senior Trump marketing campaign officers and the Russian intelligence providers.”

The Senate report portrayed a Trump marketing campaign stacked with businessmen and different advisers who had little authorities expertise and “introduced enticing targets for overseas affect, creating notable counterintelligence vulnerabilities.”

A New York Times article in 2017 stated that there had been quite a few interactions between the Trump marketing campaign and Russian intelligence throughout the 12 months earlier than the election. F.B.I. officers had disputed the report, however each the Senate report and the Treasury Division doc affirm the article’s findings.

The assertion that it was Ukraine, not Russia, that sought to disrupt the 2016 election has lengthy been each a Kremlin speaking level and a declare by Mr. Trump that overseas actors tried to assist his opponent, Hillary Clinton, relatively than him.

Mr. Trump’s obsession over Ukraine’s supposed position within the election was the impetus for a 2019 cellphone name with the Ukrainian president that was central to the primary impeachment proceedings towards Mr. Trump.

Mr. Manafort was introduced into the Trump marketing campaign in March 2016, at a time when Mr. Trump had largely sewn up the Republican presidential nomination.

Mr. Manafort and his longtime enterprise affiliate, Mr. Gates, joined the Trump marketing campaign after years of doing political consulting work in Ukraine, the place they met Mr. Kilimnik, a Russian Military-trained linguist.

The 2 males met with Mr. Kilimnik a number of instances after becoming a member of the marketing campaign, and in June 2016, Mr. Manafort turned the Trump marketing campaign chairman.

Particulars about Mr. Manafort’s relationship with Mr. Kilimnik had been revealed in 2018 as the federal government prosecuted Mr. Manafort and charged Mr. Kilimnik with obstruction of justice for making an attempt to educate potential witnesses within the investigation.

Mr. Kilimnik by no means got here to america to face costs. He’s needed by the F.B.I., and the bureau is offering $250,000 for data that would result in his arrest.