Steve Bannon urged two senior FBI officials to put their differences with the White House “behind them” at a meeting in 2017, on the day after Donald Trump asked James Comey, the then head of the FBI, to pledge his loyalty to the president.

The exchange, which occurred on 28 January 2017 and has never been publicly disclosed, offers new insights into the ways in which senior White House officials, including Bannon, Trump’s closest adviser at the time, sought to ensure the FBI saw itself as an ally of the White House.

It also raises questions about why the incident was not included in the report by special counsel Robert Mueller into Russian influence during the 2016 election, which contained detailed allegations of the ways in which Trump sought to obstruct the FBI’s investigation into the president and his campaign.

Bannon made the remarks to Andrew McCabe, who was then serving as deputy director of the FBI, and Bill Priestap, who was serving as the FBI’s assistant director of counter-intelligence. They were written up in a memo by McCabe and later raised when Bannon was questioned by US special counsel Robert Mueller’s team, according to people familiar with the matter.

Bannon: Trump facing crisis not seen since days of Abraham Lincoln Read more

According to one account, Bannon told the two officials – McCabe and Priestap – that it was time to put their past “differences” behind them, and that they were all on the same team. It is not clear what previous “differences” Bannon was referring to.

But Trump and his senior aides were scrambling at that time to respond to the discovery that Michael Flynn, the national security adviser, had lied to the FBI about discussions on sanctions with Russia’s ambassador to the US. Just two days before the Bannon meeting, Sally Yates, who was serving as deputy attorney general, told White House counsel Don McGahn about Flynn making false statements to FBI agents, and that Flynn’s talks with the Russian ambassador were themselves problematic.

Trump dined alone with Comey at the White House on the evening of 27 January, after Yates’s disclosure to McGahn, and asked the FBI director for loyalty. Mueller’s report said Bannon wanted to join the dinner, but was rebuffed by the president. Bannon had his own meeting with the two senior FBI officials the next day.

Yates was then fired by Trump on 30 January. .

While Bannon may have viewed his remarks as innocuous, legal analysts said it was highly unusual for a senior White House official to make such remarks to the FBI officials, especially at a time when the White House was facing scrutiny.

Richard Painter, who served as a White House ethics lawyer under George W Bush, said that comments that could be construed as putting pressure on the FBI were “reckless”.

“This is the type of conduct that risks obstruction charges. You do not make public comments, you do not contact the FBI or anyone at the DoJ about a pending investigation, and the reason is that those types of contacts can be seen as obstruction of justice,” Painter said. “When you say ‘we are all on the same team’, well, what does that mean?”

None of the three men who were summoned to the White House in those 48 hours –less than two weeks after Trump was inaugurated – remain in their jobs. Comey was fired by Trump four months later and McCabe was fired in March 2018, in a move that McCabe said was meant to undermine the special counsel’s investigation. Priestap retired from the FBI in December.

McCabe was dismissed from the FBI after being accused of misleading internal justice department investigators in an unrelated investigation into a press leak. While McCabe has denied lying, that matter has reportedly been referred to federal prosecutors who may still decide to charge McCabe with a crime.

This is the type of conduct that risks obstruction charges Richard Painter

McCabe’s potential legal problems could be one reason why several memos he wrote describing his interactions during the early days of the administration were not used extensively in Mueller’s report. Mueller cited two memos by McCabe on the events around Comey’s firing on 9 May 2017.

Bannon cooperated with Mueller’s investigators under a proffer agreement, when a witness may speak freely about potential crimes with assurances that their evidence will not be used against them. Such agreements sometimes evolve into formal immunity deals. The full details of Bannon’s arrangement with Mueller’s team have not been disclosed.

He was presented in Mueller’s report as having tried to stop Trump from firing Comey.

The Guardian confirmed the Bannon-McCabe-Priestap meeting occurred from several sources who spoke on the condition of anonymity.

McCabe and Priestap declined to comment.

When he was asked about the meeting, William Burck, an attorney for Bannon, told the Guardian: “Mr Bannon is not discussing anything he spoke to special counsel Mueller’s team about.”

In his recently published memoir, McCabe did not include the incident, but recalled “a series of odd interactions with the White House” that he said took place “through the winter into spring” in 2017.

McCabe said he learned a couple of days before Flynn resigned that a Trump loyalist on the National Security council had questioned McCabe’s “commitment to the Trump administration”.

A week later, McCabe wrote, White House chief of staff Reince Priebus “told me that I, personally, and the FBI as a whole, were ‘not being good partners’.”

The meeting between Bannon, McCabe and Priestap took place at a sensitive time, as Trump’s White House faced growing scrutiny over his team’s connections to Russia. US intelligence authorities had announced three weeks earlier that Vladimir Putin, Russia’s president, interfered in the 2016 election specifically to help Trump.