U.S. President Donald Trump hit out at FBI Director Christopher Wray in a tweet on Tuesday, a day after the U.S. Justice Department's (DOJ) internal watchdog said it found no evidence of political bias when the FBI began investigating contacts between Trump's presidential campaign and Russia in 2016.

Wray, in an interview on ABC News on Monday, acknowledged the numerous errors the watchdog also found and said he would took them seriously, but said the inspector general had found the probe "was opened with appropriate predication and authorization." 

Trump fired back on Twitter early on Tuesday: "I don't know what report current Director of the FBI Christopher Wray was reading, but it sure wasn't the one given to me. With that kind of attitude, he will never be able to fix the FBI, which is badly broken despite having some of the greatest men & women working there!"

What did the report conclude?

The DOJ concluded on Monday there was no political bias in the launching of a federal probe into potential collusion between the Trump campaign and Russia in 2016.

In its findings, the Department notes it saw no direct evidence to support claims of bias against then-candidate Donald Trump. 

But the report did identify inaccuracies and omissions by the FBI, specifically in the agency's handling of requests for surveillance of a former Trump campaign adviser. 

The report, written by the DOJ Inspector General Michael Horowitz, reviewed the FBI's four FISA applications made to the U.S. Foreign Intelligence Surveillance Court, as well as other aspects of the agency's "Crossfire Hurricane Investigation" into the actions of the Trump campaign. 

How did Wray respond?

FBI director Wray pledged to take action based on the report's findings.   

Wray, who took on the top job in August 2017, wrote on Monday that he has emphasized to agents, analysts and staff the "importance of doing things the right way.”  

In a response letter to the Inspector General Horowitz, Wray wrote, "I am humbled to serve alongside these dedicated men and women, and I am confident that the actions we are taking will strengthen our historic institution, ensure that we continue to discharge our responsibilities objectively and free from political bias, and better position us to protect the American people against threats while upholding the Constitution."

On several occasions, Trump has claimed, without providing proof, that the FBI planted an agent within his campaign. The report found "no evidence" of such action.  

What other reaction has there been?

Trump's Attorney General William Barr welcomed DOJ's critique of FBI's handling of the surveillance process. But he rejected the inspector general's conclusion that the FBI had sufficient reason to launch its probe. 

Opposition Democrats welcomed Horowitz's conclusion. But Congressman Jerry Nadler, the chair of the House Judiciary Committee that's currently carrying out impeachment proceedings against Trump, warned the report could provide further fuel to Trump's defenders. 

In a statement, Nadler wrote, "right-wing media will continue to prop up these conspiracy theories to deflect from the President's misconduct, but we will not be distracted by their baseless allegations."

Republicans argue the FBI depended too heavily on a dossier prepared by a former British intelligence officer, Christopher Steele. They allege Steele was funded, in part, by Hillary Clinton's presidential campaign and by the Democratic Party. 

In May 2017, Robert Mueller was appointed as a special counsel to head the FBI probe. Mueller's nearly two-year investigation led to 34 indictments, and saw some close Trump associates go to jail.  

Mueller concluded earlier this year, "If we had confidence that the president clearly did not commit a crime, we would have said that. We did not, however, make a determination as to whether the president did commit a crime... a president cannot be charged with a federal crime while he is in office. That is unconstitutional. Even if the charge is kept under seal and hidden from public view, that too is prohibited." 

(With input from agencies)