The first group of 96 prospective jurors has been sworn in.

Judge Merchan is now delivering remarks that he said will last about 30 minutes, introducing the case and explaining to prospective jurors their responsibility -- if selected -- to be fair and impartial.

Trump has been leaning forward in his seat listening, with his elbows on the desk.

Dozens of New Yorkers are now being escorted into the courtroom as prospective jurors.

Judge Merchan will deliver a summary of the case before attorneys for both parties have an opportunity to evaluate the prospective jurors' fitness to serve.

According to the pool, 96 individuals will make up the first batch to go through the laborious selection process. Merchan said approximately 200 people have been summoned to the courthouse for potential jury duty on the case.

Trump, during a lengthy break as court officials escorted jurors through security magnetometers, could be seen reclining in his chair and conversing with his attorney Todd Blanche.

Judge Merchan has issued Trump's defense team an ultimatum: Turn over their proposed defense exhibits in 24 hours or be barred from using the materials.

"You have 24 hours," Merchan said. "Anything you don't produce within 24 hours will be precluded."

Defense attorney Todd Blanche pushed back on the deadline, arguing against a prosecutor's assertion that defense withheld materials following a February exhibit deadline for "tactical reasons."

"That is completely false," Blanche said. He asked Merchan for a Wednesday deadline instead, given the demands of the trial.

Merchan declined to grant the request, highlighting the recent flurry of defense motions filed over the last few weeks.

"I don't know how you managed to get those motions out," Merchan said. "The way you choose to use your time is your business."

Judge Merchan has set a hearing on prosecutors' request to hold Trump in contempt for allegedly violating the judge's limited gag order.

After initially setting the hearing for Wednesday, April 24, he rescheduled it for Tuesday, April 23 at 9:30 a.m. ET.

The judge gave Trump's attorneys until April 19 to file their written response.

Prosecutor Christopher Conroy also asked that a copy of the order be served on Trump, and papers were then handed to Trump and defense attorney Todd Blanche at the defense table.

The first witness prosecutors with the Manhattan DA's office plan to call is former National Enquirer publisher David Pecker, according to two sources familiar with the matter.

ABC News previously reported that prosecutors planned to call Pecker as a witness, but sources now say he's expected to be the first witness to take the stand.

Pecker served as the longtime chief executive of American Media Inc., which published the National Enquirer.

Shortly after Trump announced his 2016 presidential campaign, Pecker met with Trump and agreed to act as the "eyes and ears" of the campaign by looking out for and killing negative stories about Trump, according to the Manhattan DA.

As part of the arrangement, Pecker allegedly directed a deal to pay $30,000 to a former Trump Tower doorman regarding the false allegation that Trump allegedly fathered a child out of wedlock, prosecutors say. Then-Trump attorney Michael Cohen allegedly insisted that the deal stay in place even after AMI discovered the allegation was false, and AMI paid the doorman, according to the Manhattan DA.

-Katherine Faulders