WASHINGTON — Attorney General William Barr said Tuesday that he is "reviewing the conduct" of the FBI's Russia probe during the summer of 2016, and that the Department of Justice inspector general will release a report on the FBI's use of the Foreign Intelligence Surveillance Act process and other matters in the Russia case in May or June.

"I am reviewing the conduct of the investigation and trying to get my arms around all the aspects of the counterintelligence investigation that was conducted during the summer of 2016," Barr said in public testimony before a House Appropriations subcommittee, his first since last month's release of his four-page summary of special counsel Robert Mueller's report on Russian interference in the 2016 election.

Barr made the comment during an exchange with Rep. Robert Aderholt, R-Ala., ranking member on the panel, who noted that Rep. Devin Nunes, R-Calif., had referred eight people to the FBI for investigation regarding "alleged misconduct during the Russia investigation including the leak of classified material and alleged conspiracies to lie to Congress and the FISA court in order to spy on then-candidate Trump and other persons."

The remarks came as the attorney general faced a barrage of tough questions from the Democratic-controlled House panel Tuesday morning regarding Mueller’s report, telling lawmakers he would release a redacted version of the original document "within a week."

While Barr’s opening statement before the House Appropriations subcommittee, which oversees funding for the Commerce and Justice departments and science agencies, focused on the 2020 budget request for his department, lawmakers on the Democratic-controlled committee pressed him on the Mueller report.

Subcommittee chairman Rep. José Serrano, D-N.Y., in his own opening statement, said the panel "could not hold this hearing without mentioning the elephant in the room" — the Mueller report.

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He referred to a New York Times report from last week that said the special counsel's office had already created summary documents of the report that Serrano said "were ignored in your letter." He added that, per the reporting, some investigators on the team "felt that your summary understates the level of malfeasance by the President and several of his campaign and White House advisers."

"The American people have been left with many unanswered questions; serious concerns about the process by which you formulated your letter; and uncertainty about when we can expect to see the full report," Serrano said. "...I think it would strike a serious blow to our system and yes, to our democracy if that report is not fully seen."

Rep. Nita Lowey, D-N.Y., chairwoman of the full Appropriations Committee, said in her opening statement that Barr's handling of the Mueller report had been "unacceptable," adding that the speed of Barr's summary of the lengthy document was "more suspicious than impressive."

Barr defended his handling of the document, listing several areas that he believes should be redacted, including grand jury information, information that the intelligence community believes would reveal sources and methods, information in the report that could interfere with ongoing prosecutions and information that “implicates the privacy or reputational interests of peripheral players where there’s a decision not to charge them.”

The attorney general said that Mueller is working with him and his team through the process and that they will “color code” the redacted areas in the report and provide explanatory notes describing the basis for each redaction.

He said that his original timetable “still stands” to release the report by mid-April: “From my standpoint, within a week, I will be in a position to release the report to the public.”

Lowey expressed incredulity that Barr was able to fully digest the Mueller report and compile a summary of it in 48 hours.

“It seems your mind must have already been made up,” she said.

Barr responded that “the thinking of the special counsel was not a mystery to the people of the Department of Justice prior to his submission of the report. He had been interacting, he and his people were interacting with the deputy attorney general.”

Asked whether Mueller or anyone on his team reviewed Barr's summary of the report in advance, Barr said that Mueller's team "did not play a role" in drafting that document and that he did give Mueller an opportunity an opportunity to review it, but he "declined."

He would not respond to questions from Lowey about whether he had shared any additional information from the report with the White House, or whether administration officials had seen the full document.

Barr later clarified during the hearing that before his summary was sent out, “we did advise the White House counsel’s office that the letters were being sent” and while they weren’t give the document in advance, “it may have been read to them.”

Lowey pointed out that while Barr’s summary of the Mueller report said that it was inconclusive about whether Trump obstructed justice, it also said that it did not exonerate him. Lowey added that Trump, meanwhile, has stated publicly that it represented a complete and total exoneration.

Asked who is factually accurate, Barr demurred. “It’s hard to have that discussion without the contents of that report, isn’t it?” he said.

Barr said several times during the hearing that he was technically operating under a regulation established under the Clinton administration, which he said does not provide for release of the report, and so he is relying instead on his own discretion. Former acting solicitor general Neal Katyal, who wrote the regulations, recently told MSNBC’s Rachel Maddow that the regulations don’t necessarily prescribe what Barr claims, saying there is “no excuse whatsoever” for not releasing the full report.

Republicans, meanwhile, largely looked to steer questioning away from the Russia probe. Aderholt began his series of questions about the situation at the U.S.-Mexico border. Rep. Martha Roby, R-Ala., asked Barr about the Justice Department's efforts to combat human trafficking.

Democrats have demanded that Barr release the full Mueller report, which spans nearly 400 pages. Barr, who said in a previous letter to House Judiciary Committee Chairman Jerry Nadler, D-N.Y., and Senate Judiciary Committee Chairman Lindsey Graham, R-S.C., that he planned to release the report to Congress “in mid-April, if not sooner,” also said that there would be redactions.

House Democrats had given Barr until April 2 to submit the full report to Congress, a deadline that was not met. In response, the House Judiciary Committee last week passed a resolution that authorizes Nadler to issue a subpoena for the full, unredacted report. It has not yet been issued.