President Trump sits with Attorney General Jeff Sessions last month. Trump’s White House counsel personally lobbied Sessions to not recuse himself from the Justice Department’s investigation into potential ties between Russia and the Trump campaign. (Evan Vucci/AP)

At the behest of President Trump, the White House's top lawyer called Attorney General Jeff Sessions shortly before he recused himself from the FBI investigation into Russian meddling in the 2016 election and tried to persuade him not to do so, according to two people familiar with the discussions.

By then, one of the people said, Sessions had essentially already made up his mind to step aside, and though the lawyer's phone call sparked some additional discussions, the attorney general would ultimately turn over the probe to his top deputy.

But the lobbying effort by Don McGahn, first reported Thursday night by the New York Times, could be an important episode in the very probe over which McGahn urged Sessions to maintain his authority.

After Sessions's recusal, his deputy, Rod J. Rosenstein, appointed special counsel Robert S. Mueller III to lead the investigation, and Mueller is now exploring — among other things — whether Trump attempted to obstruct justice and interfere with investigators' work. He is also investigating possible coordination between the Kremlin and the Trump campaign to influence the 2016 election.

Spokesmen for the Justice Department and the special counsel declined to comment for this story. Trump lawyer Ty Cobb declined to comment, and McGahn did not immediately return a message seeking comment.

Trump was taken aback by Sessions's recusal, and afterward, he raged to staffers and on Twitter that his attorney general had made the wrong choice. In July, he told the New York Times that if he had known Sessions would recuse himself, he "would have picked somebody else" to be attorney general. At some point, Sessions offered his resignation, but the president would not accept it.

Sessions has said publicly he isolated himself from the Russia investigation almost from the moment he took office in early February, and all the while, consulted with career officials about whether he would have to formally recuse himself because of his role as an adviser on Trump's campaign. A person familiar with his thinking said he had decided to step aside formally by late February.

On March 1, The Washington Post reported that Sessions had spoken twice with Russia's ambassador to the United States — encounters he did not disclose when asked at his confirmation hearing about contacts between members of Trump's campaign and representatives of Moscow. That report increased the public pressure on him to give up supervision of the probe.

A person familiar with the probe said McGahn had a conversation with Sessions early the next day, trying to persuade him to stay in control. Sessions, the person said, was not immediately committal. But he would soon announce to the public — not long after the news was passed to McGahn — that he was stepping aside and leaving the matter to Rosenstein.

Two months later, Trump fired James B. Comey as the FBI director, and soon after that, Rosenstein appointed Mueller to lead the probe. Mueller has been looking at the events surrounding the firing of Comey — which the president has said he did with the Russia controversy on his mind — and his examination would probably also involve examining other efforts by Trump to influence the investigation, such as Trump's request of McGahn.

Mueller has interviewed Rosenstein, who drafted a memo supporting Comey's firing and retains supervision over the special counsel, and he has obtained memos that Comey wrote about his dealings with the president. By Comey's account, the president asked him to pledge loyalty and said he hoped Comey could let go of the bureau's investigation into former national security adviser Michael Flynn, who recently pleaded guilty to lying to the FBI.

Mueller also has obtained notes from Reince Priebus, Trump's former chief of staff, indicating Priebus and Trump talked about the president urging Comey to say publicly he was not being personally investigated, according to a person familiar with the matter.

Carol Leonnig contributed to this report.