WASHINGTON –– President Donald Trump and Attorney General Jeff Sessions have had a series of heated exchanges in the last several weeks after Sessions recused himself from the Russia probe, a source close to Sessions told CNN Tuesday.

A senior administration official said that at one point, Sessions expressed he would be willing to resign if Trump no longer wanted him there.

The frustration comes at a critical juncture for Trump. Former FBI Director James Comey is set to testify Thursday about his private discussions with Trump and the Russia investigation has lapped into the White House, with questions about the President’s son-in-law and adviser, Jared Kushner.

Tuesday afternoon, White House press secretary Sean Spicer declined to say whether Trump has confidence in Sessions.

“I have not had a discussion with him about that,” Spicer said.

As of 9 p.m. ET Tuesday, the White House still was unable to say whether or not the President backs his attorney general, a White House official said. The official said they wanted to avoid a repeat of what happened when Kellyanne Conway said Trump had confidence in Flynn only to find out hours later that the national security adviser had been pushed out.

Sessions remains at the Justice Department, where a spokeswoman told CNN that he is not stepping down.

ABC News first reported Tuesday that Sessions offered to resign.

Brewing since Sessions’ recusal

Sessions recused himself from the Russia probe in March, shorty after The Washington Post reported on undisclosed meetings between him and the Russian ambassador to the US, Sergey Kislyak.

In the three months since Sessions stepped aside, the intensity of the probe has grown exponentially — culminating in Deputy Attorney General Rod Rosenstein’s decision to appoint Robert Mueller as special counsel.

The frustration between Trump and Sessions has gone both ways, with Justice Department officials upset that the President’s tweets and comments caused problems for Sessions and Rosenstein in the wake of the Comey firing.

CNN has previously reported that Trump was frustrated with Sessions’ decision to recuse himself.

Sessions was Trump’s first supporter in the Senate and was an enthusiastic backer throughout the campaign — standing with Trump through multiple controversies. And Sessions’ own team has become a part of Trump’s inner circle: former Sessions chief of staff Rick Dearborn is now Trump’s deputy chief of staff, and former Sessions spokesman Stephen Miller has evolved into a highly influential figure as Trump’s policy director and speechwriter.

After the election, Sessions was rewarded with one of the most prominent positions in Trump’s new administration, atop the Justice Department.

But pressure has been mounting on Trump over his campaign’s communications with Russians. Trump told NBC News that he fired Comey in part because of the Russia probe and Comey, in a memo about a private talk, said Trump pressured him to drop his investigation of former national security adviser Michael Flynn.