WASHINGTON – Attorney General William Barr told Congress on Tuesday that he would release a redacted version of special counsel Robert Mueller's report "within a week."

Barr used his first appearance before a House committee since the end of Mueller's investigation to offer a scattering of details about how he and other lawyers in his office were reviewing the nearly 400-page report summarizing the investigation into Russian interference in the 2016 election. Barr told lawmakers some parts of the report must remain secret because they contain grand jury information or national security secrets, and then pointedly declined to say more.

Barr would not answer questions about the details of the special counsel's investigations or whether any of its findings had been shared with the White House.

"I'm not going to say anything more about it until the report is out," Barr said.

The attorney general said Mueller and his staff were working to help remove sensitive information from the report so it could be released to Congress and the public. And he defended the summary conclusions he delivered to Congress last month and the speed with which those conclusions were made public.

“The work of the special counsel was not a mystery to the people at the Department of Justice. … There was some inkling into the thinking of the special counsel,” Barr said, referring to a March 5 meeting with Mueller at the Justice Department where the special counsel discussed his preliminary conclusions.

Lawmakers questioned Barr on his decision to release a bare-bones summary of the report last month in which the attorney general said Mueller had not found a conspiracy involving President Donald Trump's campaign and the Russian government.

The special counsel did not make a determination about whether the president's actions during the investigation amounted to obstruction. Instead, Barr and his deputy, Rod Rosenstein, separately determined that Trump's conduct did not constitute a crime.

“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,” said Rep. Jose Serrano, D-N.Y., chairman of the appropriations subcommittee on Justice. “It would strike a serious blow to our democracy if this report is not fully seen.”

Appropriations Chairman Nita Lowey, D-N.Y., also called on Barr to release the report, asserting that the attorney general’s abbreviated summary “cherry-picked from the report to draw the most favorable conclusion possible for the president.”

“Even for someone who has done this job before, I would argue that it is more suspicious than impressive,” Lowey said. Barr’s summary was delivered to Congress two days after Mueller sent the report to the Justice Department.

Barr’s testimony was meant to be about the Justice Department’s $29 billion budget request, and he drew some questions from Republicans about the agency's border-security efforts and from Democrats about its new move to ask a federal court to overturn the Affordable Care Act, commonly called Obamacare. But much of the questioning focused on the still-secret details of the special counsel's work.

Democratic lawmakers spent much of the hearing pressing Barr for additional details about his handling of the report, which he largely declined to provide, instead telling them that he understood "the importance of releasing as much of the report as I can within the law."

Barr also said he had no plans to ask for a court's permission to disclose grand jury material but said he would consult with Congress after he releases the report to determine whether he can provide additional information.

Rep. Robert Aderholt, R-Ala., dismissed the Democrats’ queries related to the Mueller report and suggested members sought to support a “grassy-knoll conspiracy theory,” a reference to the cottage industry of conspiracy that emerged after President John F. Kennedy's assassination in 1963.

The attorney general's intervention at the end of Mueller's investigation has set off a politically charged battle for access to the entire text of the special counsel's report, the fruit of a 22-month investigation that has shadowed the Trump administration since its first days.

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House Democrats vowed last week that they would seek Mueller's testimony in addition to that of Barr, who also is expected to address the matter for congressional committees in early May.

Justice, however, has defended Barr's handling of the report, suggesting that the full document was so packed with secret grand jury information that revealing even portions of it immediately would have been impossible.

Spokeswoman Kerri Kupec said last week that "every page" of Mueller's report was marked with a written warning that it could contain protected grand jury information. Federal law generally prohibits the government from revealing that information. Barr also said he would not disclose parts of the report that involved national security secrets, touched on ongoing investigations, or would implicate "the privacy and reputational interests of peripheral players."

He said officials would color-code the version of the report he releases to Congress so lawmakers would know his reason for keeping specific parts secret.

Mueller's report is not the only account of the Russia inquiry pending public release.

Barr said Tuesday that Justice's inspector general is expected to complete a separate examination of whether the FBI abused its authority to monitor a former Trump campaign aide in the coming months.

The attorney general also said he was reviewing the origins of the FBI's investigation into possible ties between the Trump campaign and Russia, launched in the midst of the 2016 presidential run. The inquiry was ultimately turned over to Mueller to complete after former Attorney General Jeff Sessions recused himself from the matter because of his work for the Trump campaign.