William P. Barr, the attorney general, met privately Wednesday evening with one of President Trump’s frequent confidants, Rupert Murdoch, the media mogul whose holdings include Fox News, which has recently become more critical of the president.

The meeting was held at Mr. Murdoch’s home in New York, according to someone familiar with it. It was unclear if anyone else attended or what was discussed. Aides to both Mr. Murdoch and Mr. Barr declined requests for comment on the meeting.

The visit took place as the impeachment inquiry into Mr. Trump by House Democrats has gathered momentum. Mr. Barr has emerged as a key defender of the president’s concerns about the investigation into Russian interference in the 2016 election. Mr. Barr was criticized in the spring for his handling of the report by the special counsel, Robert Mueller III, before it was released publicly.

Mr. Trump has sought out Mr. Murdoch’s opinion on a wide range of issues in the past, and Fox News has provided Mr. Trump with key support both as a candidate and as president.