Judge Merchan has begun hearing arguments about the admissibility of some defense exhibits, including an email communication between Michael Cohen and his one-time attorney Bob Costello's law partner Jeffrey Citron.

Defense attorney Todd Blanche argued that the exhibit could be used to impeach Cohen's testimony.

Judge Merchan said he will not allow the email into evidence. Prosecutors argued that the email was hearsay and cannot fairly offer a window into Cohen's state of mind.

"There is another layer there of hearsay," Merchan said about the email. "I don't see any probative value for impeachment purposes here at all."

"Good morning Mr. Trump," Judge Juan Merchan said as he gaveled in the proceedings.

"It's become apparent that we are not going to be able to sum up tomorrow," the judge said after taking the bench.

Merchan said it's more likely summations will take place next Tuesday, after procedural matters and the Memorial Day break.

"Either have a long break now or a long break then, and unfortunately the calendar is what it is," the judge said.

Prosecutors have entered the courtroom for Day 19 of the trial.

Trump has arrived with his entourage.

Before entering, the former president addressed reporters but ignored their questions about whether he'll testify in the trial.

Donald Trump's former attorney Michael Cohen returns to the witness stand this morning for the final time before prosecutors rest their case against the former president in his criminal hush money trial.

Prosecutors could rest their case later this morning.

Defense attorneys have not yet declared who they plan to call to testify -- including whether Trump will testify in his own defense.

Cohen, the prosecution's last major witness, is expected to complete his cross-examination by Trump's defense team before lunch.

Proceedings are scheduled to get underway at 8:45 a.m. ET with arguments over the admission of additional exhibits, after which the jury is expected back in court at 9:30 a.m.

Following the defense resting its case, Judge Juan Merchan told the parties that "summations will not be quick" and that they "will take at least a day." Jury instructions will then take at least an hour, he said.

"At the end of the day, I think the best thing we can do is to adjourn now until next Tuesday. At that time you will hear summations from the attorneys," Merchan said.

Merchan says that deliberations could begin as early as next Wednesday.

Merchan told the jury he opted to delay the summations because of this week's abbreviated schedule and his belief that "it's always ideal or best not to break up summations."

Trump's eyes were closed, his head titled back, as Merchan instructed the jury to return on Tuesday.

The jury then left the courtroom.