Embattled FBI official Peter Strzok was “smug” and “laughed off” questions during his closed-door congressional interview this week, though also told lawmakers he regrets sending the anti-Trump texts that made him the poster child for bureau bias, congressional sources tell Fox News.

Strzok spoke behind closed doors before the House Judiciary Committee on Wednesday, in his first congressional appearance following revelations of numerous anti-Trump messages he exchanged with bureau colleague Lisa Page during the 2016 campaign.

“Strzok was smug, defiant, and laughed off a lot of questions,” one congressional source told Fox News following the interview. The source also echoed earlier reports that Strzok refused to answer some questions on the advice of counsel.

Another congressional source, though, told Fox News that Strzok “said he regretted sending the texts.”

The latter revelation may come as no surprise. The discovery of those texts got him booted from the special counsel Russia probe. A recent inspector general report chastised him and other officials for anti-Trump messages. And last week, Strzok was escorted from his FBI office and lost his security clearance.

'Strzok was smug, defiant, and laughed off a lot of questions.' — congressional source

But Strzok is fighting back. And after President Trump tweeted complaints that the FBI official "refused to answer many questions," his attorney Aitan Goelman countered that his client “abided by his legal responsibility to follow the instructions of the FBI counsel, who sought to avoid the disclosure of information related to the Russia investigation.”

“It should come as no surprise that President Trump, who appears desperate to undermine the Special Counsel’s investigation, is again viciously attacking Pete for playing by the rules,” Goelman said in a statement, noting that Strzok “wants full transparency around the examination of his work.”

Further, he said the committee, which held an open hearing Thursday discussing Strzok and other issues with DOJ and FBI leaders, “denied his request for a public hearing and for the release of the full transcript.” He called anew for the committee to “release the full, unclassified transcript instead of leaking selective excerpts designed to further a partisan agenda.”

A House Judiciary Committee aide told Fox News that the committee intends to hold a public hearing with Strzok "soon," but did not comment on whether they will release the transcript from the interview.

Scrutiny of Strzok's role has intensified ever since the release of the Justice Department inspector general report, which revealed a text where Strzok vowed to “stop” Trump from becoming president.

The inspector general’s report noted that it was specifically concerned about text messages exchanged between Strzok and Page that “potentially indicated or created the appearance that investigative decisions were impacted by bias or improper considerations.”

The inspector general, Michael Horowitz, ultimately found no evidence that the anti-Trump bias among several FBI agents impacted prosecutorial decisions in the Clinton email probe.

Chairman of the House Freedom Caucus Mark Meadows, R-N.C., said during a break in the hearing Wednesday that “none of [his] concerns about political bias have been alleviated based on what I’ve heard so far.”

Horowitz last week confirmed that he is investigating whether Strzok’s anti-Trump bias factored into the launch of the FBI’s Russia investigation—a line of questioning that was raised during his closed-door interview this week.

Strzok and Page both served for a short period of time on Special Counsel Robert Mueller’s team. Strzok was reassigned to the FBI’s office of human resources following the revelations of his anti-Trump texts.