Barr's comments are a rare break with a president who the attorney general has aligned himself with and fiercely defended. But it also puts Barr in line with many of Trump's supporters on Capitol Hill who say they support the president but wish he'd cut back on his tweets.
"I think it's time to stop the tweeting about Department of Justice criminal cases," Barr told ABC News Chief Justice Correspondent Pierre Thomas.
When asked if he was prepared for the consequences of criticizing the president - his boss - Barr said "of course" because his job is to run the Justice Department and make decisions on "what I think is the right thing to do."
Barr ignited a firestorm this week after top Justice Department officials intervened in the sentencing of Roger Stone, a longtime friend and former campaign adviser to the president who was convicted of lying to Congress, witness tampering and obstruction of justice.
In a stunning reversal, the Justice Department overruled a recommendation by its own prosecution team that Stone spend seven to nine years in jail and told a judge that such a punishment - which was in line with sentencing guidelines - "would not be appropriate."
In the interview with ABC News, Barr fiercely defended his actions and said it had nothing to do with the president.
Barr said he ordered the recommendation changed before Trump tweeted criticism of the prosecutors' work as horrible and very unfair.
"I had made a decision that I thought was fair and reasonable in this particular case. And once the tweet occurred, the question was now what do I do," Barr said.
Barr's interference in his prosecutors' work led to all four of them to withdraw from the case, and one even quit the Justice Department altogether.
To read and see more of the interview, visit abcnews.com.