THE International Criminal Court’s (ICC) prosecution has asked the Appeals Chamber to throw out former Philippine President Rodrigo R. Duterte’s challenge to the court’s jurisdiction, saying Manila’s 2019 withdrawal from the Rome Statute can’t shield officials from accountability for crimes committed while the country was still a member.

In a 22-page filing dated Dec. 8, Deputy Prosecutor Mame Mandiaye Niang said the court has affirmed its jurisdiction several times in the Philippine situation — through prior arrest-warrant rulings, Pre-Trial Chamber decisions and an earlier ruling by the Appeals Chamber.

The prosecution argued that these decisions consistently establish that withdrawal does not erase obligations incurred during membership.

The case centers on whether Mr. Duterte, as Davao City mayor and later as President, bears responsibility for thousands of alleged extrajudicial killings tied to anti-drug operations that prosecutors describe as a “widespread and systematic attack” against civilians. Such allegations fall squarely under crimes against humanity, the prosecution said.

Mr. Duterte started the withdrawal process days after then-ICC prosecutor Fatou Bensouda announced a preliminary examination into the drug war deaths, according to the filing.

“Allowing withdrawal to block jurisdiction would strike at the heart of the Philippines’ status as a state party at the time of the alleged crimes,” the Office of the Prosecutor said, adding that it would undermine the very purpose of joining the ICC.

The prosecution addressed each of the four grounds raised by Mr. Duterte’s legal team, arguing that none demonstrates reversible error.

On the first ground, the defense questioned how the Pre-Trial Chamber read Article 127, which covers a state’s withdrawal from the ICC. The prosecution said the chamber was right in finding that the provision makes clear that the court keeps its authority over crimes committed before a country’s withdrawal takes effect.

It said the chamber relied on the plain meaning of the text and the overall purpose of the Rome Statute, which created the ICC, adding that this interpretation is consistent with the Vienna Convention on the Law of Treaties.

The second ground questioned whether a preliminary examination counts as a “matter under consideration” when a state withdraws. The prosecution said the term “matter” is broad enough to include the subject of a preliminary examination, no matter what stage the process is in.

It added that preliminary examinations are formal steps under the Statute — involving possible judicial actions, evidence-preservation requests, and later investigations — and are not “trivial” or informal, as the defense claimed.

On the third ground — whether “the court” in Article 127 includes the Office of the Prosecutor — the prosecution said it does. The Rome Statute defines the court to include the prosecutor and the Judiciary, and the prosecutor is the organ that evaluates information at both the preliminary and investigative stages.

For the fourth ground, which accused the chamber of misinterpreting the Statute’s object and purpose, the prosecution said the chamber properly balanced a state’s right to withdraw with the Statute’s aim of preventing impunity. Accepting the defense’s theory, it said, would allow states to evade responsibility by withdrawing once scrutiny begins.

The jurisdiction fight is taking place alongside separate but related proceedings over Mr. Duterte’s detention.

The Appeals Chamber recently denied his request for interim release, citing flight risk, risk of obstruction and insufficient assurances offered by his legal team. His plea for humanitarian release was also rejected.

A confidential medical report has been submitted to Pre-Trial Chamber I, which has asked the parties to comment by Dec. 12 as it assesses his fitness to stand trial.

With its latest filing, the prosecution urged the Appeals Chamber to dismiss the appeal “in its entirety” and affirm the court’s jurisdiction. If upheld, the case would move toward a confirmation-of-charges hearing — a step that will determine whether Mr. Duterte will stand trial for crimes against humanity connected to the drug war. — Erika Mae P. Sinaking