His comments risked inflaming Democratic concerns that Barr's views are overly in sync with Trump's and that he's determined to protect the president as he readies the release of a version of Mueller's report.
"If this is a 400-page report.to send us a four-page summary that just talks about the high-level conclusions is potentially misleading", Coons said.
Justice Department attorney Courtney Enlow said the two sides should engage after the anticipated release of the Mueller report in mid-April, arguing that they would "better understand the world we're living in". Barr concluded there was not enough evidence to take the case to court.
The letter said that Mueller did not find a criminal conspiracy between Russian Federation and Trump associates around the time of the 2016 election and that Barr did not believe the evidence in the report was sufficient to prove the president had obstructed justice.
Last week news reports suggested that members of Mueller's team are frustrated with Barr's letter, which they saw as oversimplifying their more complicated findings.
It wasn't immediately clear whether Nadler would agree to the place in line Barr had given him or whether he might insist on access to Mueller's full material at the same time the redacted document appears.
Barr also wrote that Mueller's office neither fully implicated nor exonerated Trump on the question of obstruction of justice; Barr and Deputy Attorney General Rod Rosenstein decided Mueller's findings were "not sufficient", as Barr wrote.
Barr is set to return to the House and Senate for hearings focused on the Mueller investigation.
"I feel that I have an obligation to ensure government power was not abused", Barr said.
Specifically, Barr is looking into the standard for opening counterintelligence investigations.
Graham has joined other Republicans in calling for answers about how authorities used material from the former British intelligence officer Christopher Steele, author of the infamous Russian Federation dossier, in the request for surveillance of Carter Page, a onetime junior Trump 2016 campaign aide.
Attorney General William Barr has assembled a team to review controversial counterintelligence decisions made by Justice Department and Federal Bureau of Investigation officials, including actions taken during the probe of the Trump campaign in the summer of 2016, according to a person familiar with the matter.
Barr said he did not believe the evidence in the report was sufficient to prove the president had obstructed justice.
Democrats on the committee pressed Barr for more information on the final report by special counsel Robert Mueller.
Barr's statement Wednesday that he expected to release a redacted version of Mueller's almost 400-page report next week marked a slight change from the estimate he gave Tuesday, when he said the release would be within a week.