Kerri Kupec, a spokeswoman for the department, said that officials intend to issue the report to Congress and the public.
Trump's criticism also strikes a very different tone than the White House took in the days that followed Barr's summary letter, which cleared Trump of a criminal conspiracy, though the details of the investigation remain to be seen.
Prosecutor Andrew Weissmann said Mr Mueller was still investigating interactions between former Trump campaign chairman Paul Manafort and his Russian business partner Konstantin Kilimnik as critical to the inquiry. Instead, Mueller presented evidence on both sides of the obstruction question. Barr said he and Deputy Attorney General Rod Rosenstein concluded Mueller's findings were "not sufficient to establish that the president had committed an obstruction-of-justice offense", which Democrats say warrants further examination and the release of the full report.
"We gave Mueller the assignment of to come to a conclusion and that's certainly what he's done, is finding no collusion", Turner said in response to Democrats' demands to first release the report to Congress.
Last month, Mueller submitted his nearly 400-page report to the Justice Department for review by the attorney general and Deputy Attorney General Rod Rosenstein. It will have color-coded redactions. The president again slammed the investigation moments before the Justice Department revealed the release date for the final report.
Mueller's investigation, though, led to indictments of six of Trump's advisers, along with 26 Russian nationals, including some on charges of hacking.
After Barr released his four-page letter, Trump claimed "complete and total exoneration", condemned "an illegal takedown that failed" and accused unnamed political enemies of treasonous acts.
The House Judiciary Committee voted earlier this month to authorize a subpoena for Mueller's full report and evidence, depending on what Barr turns over.
Meanwhile, the top Democrat and Republican on the House Intelligence Committee are also asking Barr to produce all of the investigative materials compiled by Mueller's team and to make Mueller and his staff available for a briefing.