Senator Francis "Chiz" Escudero on Sunday expressed his support for the thorough study of calls for the Philippines to rejoin the International Criminal Court which is now conducting its probe into former president Rodrigo Duterte's war on drugs.

Citing previous treaties entered by the Philippines, Escudero said President Ferdinand Marcos Jr.'s decision to study the country's possible return to the ICC was "right."

"For me, the president is right when he said that it should be carefully studied because we have entered treaties that are disadvantageous for us," he said in a radio interview.

"Like the FATF, we entered that treaty, hence, we got blacklisted. Malaysia did not join the treaty so whatever they do, they would not get blacklisted," he said, referring to the Paris-based Financial Action Task Force.

The FATF is an intergovernmental organization that was established in 1989 on the initiative of the G7 to develop policies to combat money laundering.

As of 2022, the FATF has retained the Philippines in its "gray list," citing its alleged failure to resolve "strategic inadequacies in countering money laundering, terrorist and proliferation financing."

"That is why the return to the ICC must be studied by the president. What would the Philippines get from re-entering it?" he stressed.

The Philippines withdrew its membership from the Rome Statute in March 2018 upon the order of Marcos' predecessor, then-president Rodrigo Duterte. The withdrawal took effect on 17 March 2019.

Duterte is accused of committing crimes against humanity before the ICC in relation to his bloody war on drugs that killed at least 7,000 people, according to government data, which was questioned by both local and international human rights groups, stressing that the actual figure is higher than the said numbers.

Five years after the country's withdrawal from the Rome Statute, several resolutions both from the House of Representatives and the Senate have been filed to urge the Marcos administration to cooperate with the ICC's investigation into Duterte's drug war.

Escudero hopes that the president's decision will be based on the "product of a well-studied decision that will benefit the country and not certain political interests."

"I hope it is not politics. I hope the decision to return to the ICC would not be a personal reason. It should be explained well by the Executive branch should they decide to return to the ICC," he stressed.

Should the Marcos administration decide to return to the ICC, the senators said the Senate may either issue a concurrence or a resolution supporting the move of President Marcos.

"The President is the chief architect of our foreign policy. The House of Representatives has no role in foreign policy. So, if he signed it that is the only time there will be a discussion about whether a Senate concurrence is needed or not," he said.

"It might be a concurrence or a resolution that urges the president to return to the ICC. If it gets two-thirds votes it will be like a ratification in a way," he added.