It would be good for the International Criminal Court (ICC) to just drop the complaint against President Rodrigo Duterte, his spokesman said on Monday.

Presidential Spokesperson Harry Roque said it was true the ICC could continue with its proceedings against Duterte, who has been accused of committing crimes against humanity due to his bloody war on illegal drugs.

"But the president has said, the matter of cooperation, well, the court will never acquire jurisdiction over him. And given the very limited number of member-states in Southeast Asia, which is just Cambodia and Timor Leste, we do not know how the court can proceed," he said in a press briefing in Camarines Sur.

"For its own good, they should drop the case rather than prove to the world that the court is inutile," he said.

While there could be no conspiracy between the ICC and the United Nations Commissioner, "but there is concerted effort to discredit the president as far as the UN Human Rights community is concerned," Roque stressed.

Duterte has ordered the Philippines' withdrawal from the Rome Statute after UN High Commission on Human Rights Zeid Ra'ad al-Hussein stated the Philippine leader needs "psychiatric evaluation" following his administration's petition before a trial court to include some 600 left-leaning individuals, including a Filipino UN rapporteur, in the terrorist list.

ICC prosecutor Fatou Bensouda is conducting a preliminary examination on the complaint filed against Duterte by a Filipino lawyer, with the backing of two opposition lawmakers, for allegedly committing crimes against humanity due to the thousands of people killed on his war on drugs.

Meanwhile, Roque said the Philippines' withdrawal from the ICC would not affect the term of office of Filipino Raul Pangalangan as ICC judge.

"The term of Judge Raul Pangalangan, who is my former colleague in UP (University of the Philippines), is fixed and he will serve, if I'm not mistaken, until 2021 or 2022," he said.

Pangalangan was elected to ICC in June 2015 and his term of office will end on March 10, 2021.

The ICC has a bench of 18 judges who are nationals of States Parties to the Rome Statute.

Judges are chosen from among persons of high moral character, impartiality and integrity who possess the qualifications required in their respective countries for appointment to the highest judicial offices.

The election of the judges takes into account the need for the representation of the principal legal systems of the world, a fair representation of men and women, and equitable geographical distribution. Celerina Monte/DMS