WASHINGTON — House Speaker Nancy Pelosi, D-Calif., said Thursday that Attorney General William Barr committed a crime during testimony last month.

"What is deadly serious about it is the attorney general of the United States of America was not telling the truth to the Congress of the United States. That's a crime," Pelosi told reporters at her weekly press conference.

"He lied to Congress. He lied to Congress," she said. "If anybody else did that, it would be considered a crime. Nobody is above the law — not the president of the United States, not the attorney general."

Asked if Barr should go to jail for lying to Congress, Pelosi paused for a few seconds, and said, “There’s a process involved here and as I said, I'll say it again, the committee will act upon how we will proceed.”

The Justice Department responded in a statement, "Speaker Pelosi's baseless attack on the Attorney General is reckless, irresponsible and false."

Pelosi was referring to testimony that Barr gave to Congress in April in which the attorney general denied knowledge of concerns raised by special counsel Robert Mueller's team over his four-page summary of Mueller's 448-page report. By the time of Barr's testimony, he had received a formal letter from Mueller dated March 27 in which the special counsel conveyed his concerns and said that Barr’s summary had caused public confusion and did not fully capture his report’s "context, nature and substance.”

At a House hearing in early April, Rep. Charlie Crist, D-Fla., asked Barr about news reports that members of Mueller's team had expressed frustration with Barr's handling of the report.

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NBC News and others reported that some members of Mueller's team were frustrated that Barr, in his initial letter to Congress summarizing Mueller's findings, had cleared President Donald Trump of obstruction of justice, and that those members believed the evidence against Trump is stronger than Barr suggested.

"Reports have emerged recently, general, that members of the special counsel's team are frustrated at some level with the limited information included in your March 24th letter that it does not adequately or accurately necessarily portray the report's findings. Do you know what they are referencing with that?" Crist asked.

Barr responded, “No, I don't. I think, I think, I suspect that they probably wanted, you know, more put out.”

Democrats pounced on those earlier comments Wednesday during a Senate Judiciary Committee hearing in which Barr testified for more than five hours on the Mueller investigation.

Pelosi emphasized that the House Judiciary Committee will take the lead on the next steps and quoted the warning the panel’s chairman, Rep. Jerrold Nadler, D-N.Y.., made at the hearing earlier in the morning in which Barr did not show up.

Nadler said, “If he does not provide this committee with the information it demands and the respect it deserves, Mr. Barr’s moment of accountability will come soon enough.”

Pelosi, who said she "lost sleep last night" over watching the Barr hearing Wednesday, still expressed some hesitation about pursuing impeachment proceedings, saying Thursday, “Impeachment is the easy way out for some of these people because they know it ends at the Senate’s edge.”

"How sad is it for us to see the top law enforcement officer in the country misrepresenting, withholding the truth from the Congress of the United States," she said.