US Attorney General William Barr has said that President Donald Trump's attacks on prosecutors, the judge and jurors in the trial of a longtime adviser undermined the Justice Department's work, adding he would not be "bullied" by anyone.
In an ABC interview, Mr Barr said Mr Trump's criticism of those involved in the case of Roger Stone "make it impossible for me to do my job."
Mr Barr spoke after his Justice Department abandoned prosecutors' initial recommendation to give the veteran Republican operative seven to nine years in prison, prompting all four prosecutors to quit the case.
Mr Trump has weighed in on Twitter all week with comments that have aroused concerns his administration is weakening the rule of law.
"I'm not going to be bullied or influenced by anybody ...whether it's Congress, a newspaper editorial board or the president," Mr Barr said.
"I cannot do my job here at the department with a constant background commentary that undercuts me," Barr said, adding: "I think it's time to stop the tweeting about Department of Justice criminal cases."
The White House said Mr Trump was not bothered by Mr Barr's remarks.
"The President has full faith and confidence in Attorney General Barr to do his job and uphold the law," White House spokeswoman Stephanie Grisham said in a statement.
Mr Trump's fellow Republicans also expressed support for Mr Barr.
Senate Majority Leader Mitch McConnell, a staunch Trump supporter, said Mr Barr was "a great choice" as attorney general.
"I think if the attorney general says it's getting in the way of doing his job, maybe the president should listen to the attorney general," Mr McConnell told Fox News.
Stone was found guilty in November on seven counts of lying to Congress, obstruction and witness tampering.
Mr Trump posted a Fox News story yesterday that accused some of the jurors of political bias. "This is not looking good for the 'Justice' Department," he tweeted.
Now it looks like the fore person in the jury, in the Roger Stone case, had significant bias. Add that to everything else, and this is not looking good for the "Justice" Department. @foxandfriends @FoxNews— Donald J. Trump (@realDonaldTrump) February 13, 2020
The Twitter attacks started on Tuesday when Mr Trump criticised US prosecutors in the case stemming from former Special Counsel Robert Mueller's investigation of Russian interference in the 2016 election to benefit Mr Trump's candidacy.
Two months in jail for a Swamp Creature, yet 9 years recommended for Roger Stone (who was not even working for the Trump Campaign). Gee, that sounds very fair! Rogue prosecutors maybe? The Swamp! @foxandfriends @TuckerCarlson— Donald J. Trump (@realDonaldTrump) February 12, 2020
Congratulations to Attorney General Bill Barr for taking charge of a case that was totally out of control and perhaps should not have even been brought. Evidence now clearly shows that the Mueller Scam was improperly brought & tainted. Even Bob Mueller lied to Congress!— Donald J. Trump (@realDonaldTrump) February 12, 2020
Is this the Judge that put Paul Manafort in SOLITARY CONFINEMENT, something that not even mobster Al Capone had to endure? How did she treat Crooked Hillary Clinton? Just asking! https://t.co/Fe7XkepJNN— Donald J. Trump (@realDonaldTrump) February 12, 2020
He called their sentencing recommendation for Stone "horrible" and a "miscarriage of justice."
Stone's friendship with Mr Trump dates back decades.
Mr Trump on Wednesday thanked Mr Barr, whom he appointed last year, for "taking charge" of the case. He also tweeted criticism of US District Judge Amy Berman Jackson, who is scheduled to sentence Stone on 20 February.
Mr Trump and the Justice Department said they had not had direct talks on the matter.
Former US Attorney Jessie Liu, who oversaw the Stone case, resigned from the Treasury Department this week after the White House dropped her nomination for a post overseeing economic sanctions, a source confirmed to Reuters yesterday.
House of Representatives Speaker Nancy Pelosi said Mr Trump's comments on the Stone case amounted to interference in the workings of the U.S. government's judicial branch.
"This is an abuse of power - that the president is again trying to manipulate federal law enforcement to serve his political interest," Ms Pelosi, a Democrat, told a news conference.
"This is not what America is about. It is so wrong."
Chief Judge Beryl Howell, the top judge on the US District Court in Washington on which Judge Jackson sits, also weighed in, saying in an unusual public statement that public criticism "is not a factor" in sentencing decisions.
Stone was one of several close Trump associates charged in Mr Mueller's probe, which Mr Trump called a "witch hunt."
His supporters are pushing for a presidential pardon. Mr Trump has declined comment.
The Republican-led Senate last week acquitted Trump on impeachment charges brought by the Democratic-led House accusing him of abuse of power and obstruction of Congress stemming from his dealings with Ukraine.