The judge in former Trump campaign chairman Paul Manafort's trial suggested to a prosecutor for special counsel Robert Mueller that he is "so frustrated" that there were tears in his eyes.

Bloomberg reported that U.S. District Judge T.S. Ellis III made the comment to prosecutor Greg Andres during a discussion out of earshot of the jury and members of the media.

"I understand how frustrated you are," Ellis said. "In fact, there's tears in your eyes right now.''

Andres disputed Ellis's statement, to which the judge replied, "Well, they're watery."

Tensions have existed between the prosecutors and Ellis throughout the trial. The judge has asked members of both sides to refrain from making facial expressions that might influence the jury.

He has also criticized Mueller's team for presenting too much evidence on Manafort's spending, arguing that spending on luxuries is not a crime.

Bloomberg reported that Ellis and Andres had other tense private conversations during the trial on Monday, during which former Manafort associate Richard Gates testified that he and Manafort committed crimes.

Andres claimed that Ellis was preventing him from asking essential questions for the trial. Ellis disputed that he was prioritizing speed over the prosecutor's arguments.

The pair have had other confrontations during the trial, according to Bloomberg.

"Look at me when you're talking to me,'' Ellis said to Andres at one point.

"I'm sorry, judge, I was,'' the prosecutor replied.

"No, you weren't,'' Ellis said. "You were looking down.''

"Because I don't want to get in trouble for some facial expression,'' Andres said. "I don't want to get yelled at again by the court for having some facial expression when I'm not doing anything wrong, but trying my case."

Manafort is on trial for alleged financial crimes related to his work for a pro-Russia political party in Ukraine. The charges are being brought as part of Mueller's investigation into Russian interference in the 2016 presidential election, including whether members of the Trump campaign coordinated with Moscow.