American rapper A$AP Rocky was brought to court in handcuffs for the second day of his assault trial in Sweden on Thursday, in a case being monitored from the courtroom by US President Donald Trump's special envoy for hostage affairs.

The prominent international artist, whose real name is Rakim Mayers, pleaded not guilty to assault charges on Tuesday after being detained following a street brawl in the Swedish capital Stockholm on June 30.

He is expected to address the court with his testimony on Thursday.

Presidential Hostage Affairs Envoy Robert C. O’Brien greeted A$AP Rocky’s mother with a handshake as proceedings began.

O’Brien’s presence in the courtroom, for the second day of the trial, marks the latest move from the Oval Office in a trial that is being closely watched by Trump and has caused a diplomatic quarrel between the President and his Swedish counterparts.

It comes after O’Brien told CNN on Tuesday that Trump wants the rapper and his two co-defendants, Bladimir Corniel and David Rispers, to “come home as soon as possible.”

Trump has repeatedly pressed Swedish Prime Minister Stefan Löfven to free A$AP Rocky on Twitter, but his efforts have been rebuffed by the country’s government.

The second day of the trial began with continued interrogation of the alleged victim, who says A$AP Rocky and his entourage assaulted him by kicking and beating him with a glass bottle or part of one while he lay on the ground.

The alleged victim told the rapper’s lawyer, Slobodan Jovicic, he was surprised by the behavior of A$AP Rocky and his entourage, whom he claimed were pushing him away as he searched for his friend.

Jovicic also played a clip from a cell phone where it appears the victim was trying to strike the rapper’s bodyguard with his fist and rings, followed by an attempt to hit him with headphones.

A$AP Rocky is expected to testify later on Thursday. Jovicic maintains his client did not commit any crime. The rapper asserts that he was acting in self-defense when he threw the victim to the ground and stepped on his arm.

The trial, at a packed Stockholm District Court, has attracted the world’s media, and judge Per Lennerbrant told the courtroom on Thursday he wanted its focus to remain on the incident in question.

“This case is about an alleged assault that happened here in Stockholm. Nothing else. I want to say this to everyone, ahead of today’s questioning,” he said at the start of proceedings.

On Tuesday, the trial’s first day, some audience members were audibly sobbing and shaking their heads as Swedish public prosecutor Daniel Suneson showed evidence, including surveillance footage from the burger restaurant where the fight began.

In photos of the crime scene displayed to the court, a broken glass bottle was visible on the street where the brawl took place and a fragment of what appeared to be the same bottle could be seen stuck in A$AP Rocky’s sweater.

Footage of the altercation posted by TMZ and clips shared by A$AP Rocky himself, which have been at the heart of the investigation, were also played in court on Tuesday.

The trial is set to conclude on Friday, when closing arguments will be made, but Lennerbrant suggested on Thursday that proceedings are running behind schedule and a further day may be needed.