The president's criticism of Mr. Sessions this week is just the latest blast directed at his attorney general.
His advisers were also surprised by his tweet - which slammed Sessions for referring a matter to the inspector general's office that has "no prosecutorial power" - because they had never heard Trump articulate such complaints at that level of detail before.
"I spent 15 years in that department, I love that department, I honor that department and will do my best to be your attorney general", Sessions emotionally exclaimed to the House Judiciary Committee in November. Trump himself appointed Sessions as the head of the Department of Justice.
Trump had lashed out earlier at Sessions for asking the Justice Department's internal watchdog, who was nominated in 2011 by President Barack Obama, to investigate allegations of surveillance abuse rather than using the department's lawyers.
White House Press Secretary Sarah Huckabee Sanders said the White House supports efforts to investigate the FISA program, which allows US intelligence and law enforcement officials to obtain secret surveillance orders on Americans suspected of being foreign agents.
Amid President Trump's continued frustration about spying on his campaign in 2016, the White House was noncommittal Thursday when asked whether the president wants to fire Attorney General Jeff Sessions.
Horowitz operates independently within the department.
On Wednesday, he took to Twitter to attack Sessions again.
Trump in this period also ordered his then-chief of staff, Reince Priebus, to get a resignation letter from Sessions. Isn't the I.G.an Obama guy?
Sessions was prepared to accept the consequences, but the objective wasn't to pick a fight, the source said - "he's still loyal to the President". But clearly the motive in removing Jeff Sessions has to be that he recused himself, he refuses to stop the special counsel's investigation.
Trump has often criticized Sessions on a variety of fronts, including the attorney general's decision to recuse himself from the Russian Federation investigation, a decision that led to the appointment of Special Counsel Robert Mueller.
Three top Justice Department officials were spotted dining together at an upscale Washington restaurant on Wednesday night, according to a source who saw them there.
But Mr Trump has frequently targeted Mr Sessions over Mr Mueller's operation, which is also examining whether Mr Trump has obstructed the Russian Federation investigation.
Mr Trump has since been relentlessly pressuring Mr Sessions to investigate political rivals.
The office has been working on a separate review of the FBI's handling of the Hillary Clinton email investigation under former director James Comey, but that report is not late and is expected to be released around March or April.
But he's wrong to say the report is late.
Justice Department veterans have long anxious that Trump's repeated public attacks on the department and the FBI are undermining the legitimacy of those agencies, which could have lasting damage to federal law enforcement.