Congress should investigate how transcripts of phone calls involving President Trump and his Australian and Mexican counterparts were leaked to the press, the Senate Intelligence Committee’s top Democrat said Thursday.

Sen. Mark Warner of Virginia described the unauthorized disclosure of White House transcripts this week as “absolutely” troubling, The Daily Beast reported Thursday, and endorsed investigating the leak in either the House or Senate.

“A president of the United States, a governor would tell us they’ve got to be able to have confidential conversations,” Mr. Warner, a former governor of Virginia, told the news site.

“And I think it was disgraceful that those [came out],” the Democrat added.

Mr. Warner’s comments came on the heels of The Washington Post’s publication Thursday morning of transcripts of previously disclosed phone calls Mr. Trump had with Mexican President Enrique Peña Nieto and Australian Prime Minister Malcolm Turnbull during his second week in office. Mr. Trump argued in favor of his proposed border wall during a January 27 discussion with the Mexican president, and he called a previously approved refugee deal between the U.S. and Australia “ridiculous” during his tumultuous talk with Mr. Turnbull, the transcripts revealed.

The leak may be “reflective of a chaotic White House,” Mr. Warner said, but warrants a congressional inquiry nonetheless.

“Whether that is Intel or Judicial [committees] looking into it, somebody ought to,” he said.

The White House declined to comment on the leaked transcripts Thursday except to call it a national security matter potentially capable of complicating the president’s ability to negotiate with foreign leaders.

Unauthorized disclosures have plagued the Trump administration persistently since the president’s inauguration January 20, and a Senate report released in early June found that the current White House has endured an average of one leak a day.

The Justice Department separately held a press conference Friday morning devoted to the recent wave of unauthorized disclosures and said federal prosecutors are currently conducting three times as many investigations into leaks than at the end of former President Obama’s administration.