(CNN) House Speaker Nancy Pelosi said on Wednesday that Attorney General William Barr is "going off the rails," while referencing Barr's recent testimony on Capitol Hill .

"Let me just say how very, very dismaying and disappointing that the chief law enforcement officer of our country is going off the rails, yesterday and today," Pelosi said during a news conference at a House Democratic retreat in Virginia.

"He is the attorney general of the United States of America, not the attorney general of Donald Trump," she added.

Since special counsel Robert Mueller's investigation ended, Democrats have been knocking Barr for not committing to releasing the full, unredacted special counsel report to Congress.

On Wednesday, Democrats also strongly criticized the attorney general over a comment he had made during testimony on the Hill, in which he said, "I think spying did occur," in reference to the Trump 2016 presidential campaign.

Barr has repeatedly defended his handling of the Mueller report by telling lawmakers he will be as transparent as he possibly can with respect to releasing information, saying he will make public everything that can be made public under law.

Barr also told lawmakers on Wednesday that he will be looking into the "genesis" of the FBI counterintelligence investigation that began in 2016 of potential ties between members of Trump's presidential campaign and the Russian government.

"I think spying on a political campaign is a big deal," Barr said, echoing some of the more inflammatory claims lobbed by the President for months but declining to elaborate on his concerns.

Pelosi said during her news conference, however, that she isn't confident that Barr will conduct his review appropriately.

Asked specifically if she had confidence that Barr would conduct his investigation in an appropriate way, Pelosi simply answered: "No."

Pelosi said she had confidence in the intelligence she's been given about the origins of the Russia probe but could not confirm or deny what she's been told as a member of the gang of eight, a shorthanded reference to the top leaders and intelligence chairs from both parties and congressional chambers.

"I have confidence, yes, in the intelligence and from what I have seen," she said.

"I don't trust Barr, I trust Mueller," she told the AP.