Trump will never 'let it go' that Jeff Sessions' recusal from Russia probe was 'original sin': Priebus The former chief of staff also said the president isn't "going to let it go."

 -- The former chief of staff to President Donald Trump said the president sees Attorney General Jeff Sessions' recusing himself from the Russia probe as "the original sin" and he will never "let it go."

In response to the latest war of words between Trump and Sessions, another top ally of the president, Chris Christie, an ABC News contributor and former New Jersey governor, said, “If the president has absolutely no confidence in the attorney general, then the president has to act, not just criticize, but act.”

On “This Week” Sunday, former White House Chief of Staff Reince Priebus told ABC News’ Chief Anchor George Stephanopoulos that although he believes Sessions should stay in his post, Trump has a deep, abiding complaint about his attorney general.

“I don't think that it would be good for the president for -- for Attorney General Sessions to leave,” Priebus said. “But I also think the president has made up his mind in regard to how he feels about the recusal.”

“He feels like that was a -- the first sin, the original sin, and he feels slighted by it,” Priebus continued. “He doesn't like it, and he's not going to let it go.” Sessions recused himself on March 2, 2017 from the Department of Justice’s investigation into alleged Russian interference in the U.S. presidential election and possible ties to Trump associates.

Sessions recused himself on March 2, 2017 from the Department of Justice’s investigation into alleged Russian interference in the U.S. presidential election and possible ties to Trump associates.

Earlier that day, Trump had said he had confidence in Sessions and didn’t think he should recuse himself. Deputy Attorney General Rod Rosenstein, whose Senate confirmation to his post came in April, was then in charge of the probe, and in May he appointed Robert Mueller as special counsel to lead the investigation.

Rosenstein said of the appointment, “What I have determined is that based upon the unique circumstances, the public interest requires me to place this investigation under the authority of a person who exercises a degree of independence from the normal chain of command.”

Since at least the summer, Trump has more than once publicly expressed frustration with his attorney general.

In an interview with The New York Times in July, Trump slammed his attorney general’s decision to remove himself from involvement in the Russia probe.

"Sessions should have never recused himself, and if he was going to recuse himself, he should have told me before he took the job, and I would have picked somebody else," Trump said in the interview.

Trump revived his criticism of Sessions on a different matter last week, tweeting on Wednesday that the attorney general should not have assigned the Department of Justice inspector general to investigate the issuance of surveillance warrants during the election.

The probe by the Justice Department's inspector general comes after Republican staff of the House Intelligence Committee alleged in a memo last month that the Department of Justice and FBI abused their power when they approved a surveillance warrant for Trump campaign adviser Carter Page.