WASHINGTON — Attorney General William Barr on Monday said he would resign next week, ending a tenure in which the President Donald Trump loyalist carried the administration's "law and order" message but ultimately dealt the most credible blow to Trump's unfounded claims that the 2020 election was littered with fraud, according to a CNN report.

His departure was announced by the President on Twitter moments after the counting in the Electoral College put President-elect Joe Biden over the 270 votes needed to formally secure the presidency.

Despite escalating tensions between Trump and Barr that had burst recently into public view, the President framed Barr's departure as amicable.

"Just had a very nice meeting with Attorney General Bill Barr at the White House. Our relationship has been a very good one, he has done an outstanding job! As per letter, Bill will be leaving just before Christmas to spend the holidays with his family," Trump tweeted, announcing the news.

"Deputy Attorney General Jeff Rosen, an outstanding person, will become Acting Attorney General. Highly respected Richard Donoghue will be taking over the duties of Deputy Attorney General. Thank you to all!"

Despite Trump's upbeat message, he had been seriously considering firing his attorney general as recently as Sunday, people familiar with the matter said, though officials did not believe he would go through with dismissing Barr immediately.

Over the past several months aides have discouraged Trump from firing Barr. The President seemed to find a compromise way of seeing Barr out by tweeting about his "very good" relationship with him.

But the two men's relationship was not, by aides' estimations, very good. Trump on Friday again told officials in a meeting he wanted to fire Barr, and over the weekend did not seem moved off his position. Still, a White House official said Barr was not forced out or fired.

"He wasn't asked to resign," the official said, insisting there were no fireworks during the meeting between Trump and Barr on Monday afternoon. "It was a very amicable meeting."

Earlier in the day, White House press secretary Kayleigh McEnany said in an interview on Fox News that Trump had been frustrated with Barr in recent days.

In his letter, Barr said that allegations of voter fraud would continue to be reviewed, despite affirming earlier this month there had been no widespread evidence of widespread fraudulent voting. He also praised the President for persisting despite what he described as relentless political opposition.

"Your record is all the more historic because you accomplished it in the face of relentless, implacable resistance," Barr wrote. "No tactic, no matter how abusive and deceitful, was out of bounds," Barr went on. "The nadir of this campaign was the effort to cripple, if not oust, your administration with frenzied and baseless accusations of collusion with Russia."

Barr repeatedly and unapologetically prioritized Trump's political goals while furthering his own vision of expansive presidential power. In his most notorious move, Barr delivered a misleading summary of special counsel Robert Mueller's report, essentially clearing Trump in the Russia probe, which drew a sharp rebuke from Mueller himself.

He remained steadfast in his support of the president heading into Election Day, including by launching various operations across the country to combat violence and drug trafficking and reiterating Trump's message not to participate in mail-in voting prior to the presidential election.

He also appointed a special counsel to continue investigating one of Trump's longtime infatuations, that intelligence and law enforcement violated the law in investigating the 2016 Trump campaign.

But the decision from the former attorney general to rebuke the president's false claims of widespread fraud in his loss to Democrat Joe Biden represented a final failure of Trump's often successful attempt to weaponize the Justice Department as a personal and potent political weapon.

Following the 2020 election, Trump's legal team filed dozens of civil lawsuits in federal and state courts across the country in an effort to prove that Biden did not fairly win the election. Barr told the Associated Press in an interview on Dec. 1 that the Justice Department had not found any such evidence.

"To date, we have not seen fraud on a scale that could have effected a different outcome in the election," he said.

The President was frustrated with his attorney general's comments to the AP and had a "contentious," lengthy meeting at the White House the day they were published, according to a person familiar with the meeting. — Agencies