Trump lawyer Chris Kise continued to spar with state attorney Louis Solomon during the testimony of Mazars General Counsel Bill Kelly.

After Solomon objected to a question posted in Kelly's cross-examination, Kise interjected to call out Solomon for being hypocritical about the bounds of acceptable testimony.

"Everything in this courtroom concerns me and my client, including your health," Kise said, referring back to his earlier concern about a courtroom COVID-19 outbreak.

"Thanks for your concern," Solomon responded offhandedly.

Trump and his attorneys have adjusted their seating compared to past days, possibly due to health concerns, so that Trump and Kise are sitting further from the state attorneys.

Before today's first witness entered court, Trump attorney Chris Kise asked Judge Engoron to postpone today's proceedings after five members of the New York attorney general's team tested positive for COVID-19.

Describing the attorney general's conduct as "beyond irresponsible," Kise said that his team did not get adequate notice about the COVID exposures despite having close contact with positive individuals.

"Nothing else matters except for pursuing President Trump," Kise said. "We have the leading candidate for president of the United States in the courtroom today."

"The attorney general's office knew on Wednesday and didn't tell any of us," defense attorney Clifford Robert said. "We are truly in an outbreak."

Engoron declined to grant their requested delay.

In a statement, a spokesperson for New York Attorney General Letitia James said the state has complied with all CDC guidelines.

"Our office properly notified the court and defendants' counsel, and the court decided to proceed with trial today. If there were any concerns, defendants could wear masks today or at any point, but they have opted not to," the spokesperson said.

Trump called his former lawyer Michael Cohen a "proven liar" and "felon" as Trump entered the courtroom for his civil trial this morning.

"He's a felon, served a lot of time for lying, and we're just going to go in and see and I think you'll see that for yourself," Trump told reporters outside court.

Cohen pleaded guilty in 2018 to two separate criminal cases and eventually spent more than 13 months in prison -- but said that it was Trump who caused him to "follow a path of darkness."

-ABC News' Ricardo Montero contributed to this report.

Exiting his New York City apartment this morning, Michael Cohen told reporters he was "looking forward" to seeing Trump in court.

"It's been five years since we've been in the same room," Cohen said.

Cohen preemptively defended the credibility of his testimony and reiterated that he previously perjured himself "concert with and for the benefit of Donald J. Trump."

"My credibility should not be in question," Cohen said.

-ABC News' Eric Avram contributed to this report.

Donald Trump Jr. struggled to answer questions when pressed about why former Trump Organization CFO Allen Weisselberg departed the family's firm.

"Because some legal issues he got himself into," Trump Jr. said, declining to offer specifics about Weisselberg's guilty plea on tax evasion charges last year.

Previously giving lengthy answers to questions about his background and even smiling with the judge, Trump Jr. appeared tense on the witness stand as he answered questions about Weisselberg.

"The specific event was he was indicted," Trump Jr. said.

He added that when began working for the Trump Organization as an executive vice president in the 2010s, Weisselberg outranked him. Trump Jr. would seek Weisselberg's approval for certain business decisions such as refinancing loans.

"Who is above you in your role as an executive vice president in the Trump Organization?" state attorney Colleen Faherty asked.

"Obviously I would have reported to my father in that period of time … people like Allen Weisselberg would have still been senior to me," Trump Jr. said of that time period.

Trump Jr. said he gained more responsibility in 2016 when his father became president and he was named a trustee of his father's revocable trust. He said that he, Weisselberg and his brother Eric Trump became a kind of triumvirate running the Trump Organization.

"We stopped reporting to my father on decisions involving the business," Trump Jr. said.

That relationship broke down once Weisselberg got himself into "legal issues," Trump Jr. said. He testified that he could not recall the circumstances of Weisselberg's exit, including the multimillion-dollar severance deal that Weisselberg received, which Weisselberg faced questions about during his own testimony earlier this month.

"I have no knowledge of the specifics of how it happened. He is no longer working at the Trump Organization," Trump Jr. said of the former CFO.