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 has arrived in court for the anticipated testimony of his former lawyer Michael Cohen.

New York Attorney General Letitia James is also attending the trial this morning.

James took her usual seat at the front of the courtroom's gallery, directly behind her team of lawyers at the counsel table.

The courtroom itself is nearly at capacity, with attendance matching the number of observers during the trial's opening statements.

Former President Donald Trump's plan to deliver part of his closing argument Thursday, as reported yesterday by ABC News, is now in doubt after he failed to meet a deadline to agree to limitations imposed by Judge Arthur Engoron.

According an email exchange between Engonon and defense counsel that was posted to the public docket Wednesday, Engoron said that Trump would have to follow the case's limited gag order, and that he would not be allowed to "impugn" the New York attorney general or her staff -- limitations that Trump attorney Chris Kise rejected, calling them "untenable."

"The limitations I am imposing, in my absolute discretion, are not subject to further debate. Take it or leave it," Engoron replied on Jan. 9, according to the email thread.

When Trump's lawyers missed the first deadline set by Engoron, the judge determined that Trump could not testify. Kise then responded that he did not see the deadline and requested that the closing arguments be postponed because of the death of Melania Trump's mother on Tuesday.

"I am sad to advise the Court that Mrs. Trump's mother passed away this evening. Because of the challenges presented by this deeply personal family matter, President Trump has asked that I request the Court postpone the date for closing argument," Kise wrote yesterday.

Engoron promptly denied the request and said the closings would continue as planned.

"On balance, going forward makes the most sense. Please tell Mr. Trump that I am sorry," Engoron wrote.

Kise informed Engoron that Trump still planned to attend the closings and speak.

"Despite the fact that his Mother-in Law, who he was very close to, passed away late last night, President Trump will be speaking tomorrow," Kise said in an email this morning.

When Engoron asked for assurance that Trump agreed to his rules, Kise pushed back, writing, "You are not allowing President Trump, who has been wrongfully demeaned and belittled by an out of control, politically motivated Attorney General, to speak about the things that must be spoken about."

"I won't debate this yet again. Take it or leave it. Now or never. You have until noon, seven minutes from now. I WILL NOT GRANT ANY FURTHER EXTENSIONS," Engoron replied at 11:54 a.m.

After Kise failed to respond, Engoron emailed him at 12:12 p.m. that he assumed Trump would not be speaking and that their email exchange would be posted to the court's public docket.

Responding to the development, Trump's legal spokesperson, Alina Habba, said in a statement to ABC News: "Is anyone surprised anymore?"