Former national security adviser Michael Flynn was warned by senior members of then President-elect Donald Trump’s transition team about the risks of his contacts with the Russian ambassador weeks before the December call that led to Flynn’s forced resignation, current and former US officials said.

Flynn was told during a late November meeting that Russian Ambassador Sergey Kislyak’s conversations were almost certainly being monitored by US intelligence agencies, officials said, a caution that came a month before Flynn was recorded discussing US sanctions against Russia with Kislyak, suggesting that the Trump administration would re-evaluate the issue.

Officials were so concerned that Flynn did not fully understand the motives of the Russian ambassador that the head of Trump’s national security council transition team asked Obama administration officials for a classified CIA profile of Kislyak, officials said. The document was delivered within days, officials said, but it is not clear that Flynn ever read it.

The previously undisclosed sequence reveals the extent to which even some Trump insiders were troubled by the still-forming administration’s entanglements with Russia and enthusiasm for a friendly relationship with the Kremlin.

The failed efforts to intervene with Flynn also cast harsh new light on a national security adviser who lasted just 24 days on the job before revelations about his discussions with Kislyak — and misleading accounts of them — forced him to resign.

Robert Kelner, a lawyer for Flynn, declined to comment.

Providing the Kislyak bio was seen by Obama officials as part of an effort “to make sure the new team had a full appreciation of the extent of the threat from Russia,” a former US official said.

The perceived need to impress this point upon Flynn added to the growing concerns among senior members of the Obama administration, who at the time were still coming to grips with the scale of Russian interference in the 2016 election and were worried that any punitive measures they imposed might be rescinded when Trump was sworn in.

The request for the Kislyak document came from Marshall Billingslea, a former senior Pentagon official in the George W. Bush administration who led Trump’s national security transition team from November until shortly before Trump’s inauguration.

Billingslea, who declined requests for comment, was nominated this week for a high-level position in the Treasury Department overseeing efforts to disrupt terrorist financing.

A former deputy undersecretary of the Navy, Billingslea was among a small group of experienced national security hands on the Trump transition whose entrenched scepticism toward Russia seemed at odds with the pro-Moscow impulses of Flynn and the incoming president, according to the officials who spoke on the condition of anonymity to discuss Trump personnel and decision-making.

Others included Samantha Ravich, a deputy national security adviser to Vice-President Richard B. Cheney; and Christopher Ford, a former State Department official who now works as a special assistant on counterproliferation issues in the Trump White House.

Ravich declined to comment. A spokesman for the National Security Council did not respond to requests for comment from Ford.

The Trump administration has taken a harsher tone toward Russia in recent weeks after the Syrian government, which is backed by Moscow, used chemical weapons on civilians. Secretary of State Rex Tillerson last month accused Russia of being “incompetent or complicit” in the attack, and CIA Director Mike Pompeo described Russian President Vladimir Putin as “a man for whom ‘veracity’ doesn’t translate into English.”

But Trump has pointedly refused to employ such language himself and this week renewed his scepticism that Russia was responsible for a hacking and propaganda campaign targeting last year’s presidential race — a position held by the president that is at odds with the unanimous view of US intelligence agencies.

Asked during a recent CBS interview whether he believed the allegations of Russian meddling, Trump said, “I’ll go along with Russia. Could’ve been China, could’ve been a lot of different groups.”

The unusual steps taken by transition officials working with Flynn suggest that internal tensions over Russia began almost immediately after Trump’s victory in an election that Moscow sought to help him win, according to a declassified report by US intelligence agencies.

Billingslea was tapped in early November to head the effort to assemble a national security team for Trump in Washington, leading a so-called “landing team” that was based in offices at the General Services Administration headquarters in Washington but also had space in the Old Executive Office Building adjacent to the White House.

The effort was hampered by confusion in the election’s aftermath, friction among factions competing for influence with Trump, and communication difficulties created by an arrangement in which the landing team was based in Washington, but Flynn and his deputy, K.T. McFarland, spent almost all of their time at Trump Tower in New York.

In an attempt to improve coordination, the group scheduled a November meeting in Washington, a session attended by Flynn as well as about a dozen aides and staff members from other departments, officials said. Others also participated by phone.

As Flynn went through his upcoming appointments, he mentioned that he was being inundated with requests for meetings from diplomats. Most would have to wait to get access to Trump’s designated national security adviser, a position that would give Flynn enormous influence in the White House. Flynn then revealed that he’d already scheduled a conversation with Kislyak.

Meetings with foreign counterparts are commonplace for incoming national security advisers. But the reference to Kislyak raised eyebrows among officials who had spent much of their careers treating Russia as an adversary and avoiding encounters with Russian officials who might be engaged in espionage.