The Democratic chairman of the House Judiciary Committee threatened to subpoena Acting Attorney General Matthew Whitaker at the end of a contentious Capitol Hill hearing Friday.

Rep. Jerry Nadler, D-N.Y., closed the hearing, which saw many tense back-and-forth exchanges between Whitaker and Democrats on the panel, by telling Whitaker he owes the committee answers to follow-up questions. Nadler added that he will likely ask Whitaker to return for another round of questioning at some point in the future, possibly under subpoena.

"Before we adjourn, I want to note for the record, Mr. Whitaker, you owe us responses on a number of issues raised here today," said Nadler, who then rattled off several of the questions.

"We require answers to these questions. I ask the department to work with the committee to provide them. As part of that work, I fully intend to call you back for an interview, under subpoena if necessary, and I expect more fulsome answers at that time."

Friday's hearing almost didn't happen after Whitaker said Thursday he would not attend if the Democrat-led committee forced him to do so. He ultimately relented later Thursday, saying he would apper as scheduled.

The hearing was supposed to cover routine oversight of the Department of Justice, but several Democrats used the opportunity to ask Whitaker about his background and his private conversations with President Donald Trump.

The committee's ranking member, Rep. Doug Collins, R-Ga., said numerous times that Democrats were asking questions outside the hearing's scope, but Nadler overruled him.