The International Criminal Court (ICC) Pre-trial Chamber I has set former president Rodrigo Duterte's confirmation of charges hearing on Sept. 23, six months after his arrest early this week.

Pre-Chamber Trial I presiding judge Judge Iulia Antoanella Motoc said the date might be postponed by the chamber depending on the progress of the proceedings either on its own motion or upon the request of the prosecution or the defense.

The confirmation of charges hearing is when the chamber decides whether there's sufficient evidence against a suspect, determining if the case should proceed to trial.

"There will be a full procedure that will unfurl, leading up to the confirmation of charges that will enable Mr. Duterte to raise all the matters... with regard to the warrant of arrest, with regard to the crimes committed, with regard to the charges and other matters associated with his arrest and the matters of jurisdiction of the court," Motoc said.

The ICC allowed Duterte to attend the hearing via video link, citing Duterte's long journey. His counsel, former executive secretary Salvador Medialdea, was present in the courtroom.

During the hearing, a seemingly frail Duterte, clad in a suit in a shade of blue, was asked to confirm his identity. He was also made aware of his rights, which include the possibility of applying for interim release pending trial.

Judge Motoc clarified that the initial hearing was not the start of the trial. No evidence was collected or presented, and the issue of Duterte's innocence or guilt was not addressed.

In his remarks during the hearing, Medialdea presented the circumstances behind the delivery of Duterte to the ICC. He said the former president was "bundled into a private aircraft and summarily transferred" to the Hague.

"To us lawyers, this will be called an extrajudicial rendition. To the less legally inclined, it is a pure and simple kidnapping," he said.

Medialdea also claimed that Duterte was denied all access to legal recourse in Manila, citing "political score-settling."

"With this in mind, it is not surprising that my client was abducted from his country," he said, noting that Duterte's arrest and surrender to the ICC was a "gross abuse of process."

Medialdea likewise said that he and Duterte only had an hour to discuss the hearing and that he was not able to present the former president a hard copy of the arrest warrant. Judge Motoc countered, saying Duterte was informed of this when he arrived at the ICC.

Meanwhile, with regard to health issues, Motoc said the court has taken specific measures and that the court's doctor was of the opinion that Duterte was fully mentally aware and fit.