THE HAGUE -- Former Philippine president Rodrigo Duterte's initial appearance is scheduled for Friday, the International Criminal Court (ICC) announced on Thursday.

"During the initial appearance hearing, the judges will verify the identity of the suspect and the language in which he is able to follow the proceedings. He will be informed of the charges against him and of his rights under the ICC Rome Statute," The Hague-based court said on its website.

Duterte, 79, was detained on Tuesday morning upon his return to Manila from abroad, following an arrest warrant issued by the ICC over his "war on drugs" campaign, a move he has questioned.

He was surrendered to the custody of the ICC on Wednesday after being flown from Manila to the Netherlands.