PRESIDENT Rodrigo Duterte on Monday admitted that he was using marijuana, an illegal substance in the Philippines, to remain awake amid his 'killing' schedule during international summits.

In his speech during the awarding ceremony of the Association of Southeast Asian Nations (Asean) National Organizing Council in Malacañang, Duterte lamented the hectic schedule he and other officials followed during the recently concluded Asean summit in Singapore last month.