MANILA (Reuters) - Philippine President Rodrigo Duterte on Wednesday defended his bloody war on drugs, telling Southeast Asian lawyers he had been “demonized” and denying allegations of state-sponsored killings of drug dealers and users.

Philippine President Rodrigo Duterte gestures as he delivers his speech during the 116th Police Service Anniversary inside the Philippine National Police (PNP) headquarters in Quezon city, metro Manila, Philippines August 9, 2017. REUTERS/Romeo Ranoco

Duterte’s crackdown has caused international alarm, and domestic polls have shown growing scepticism about the 16-month old campaign that has killed thousands of mostly urban, poor Filipinos.

His government’s human rights record has been strongly criticized by Western countries, and is one of the issues U.S. President Donald Trump plans to raise on a visit to Manila next month to attend a regional summit.

“I know that I have been demonized,” Duterte said, invoking God and his oath as a lawyer as he offered his assurance. “The extra judicial tag that has been placed on me is simply not true.”

He was speaking to members of the ASEAN Law Association, attending a commemorative session in Manila, the host of this year’s activities of the Association of Southeast Asian Nations grouping.

Duterte spoke for more than an hour after delivering a prepared speech, as he defended the campaign and explained why many of those killed were from among the poor.

He used United Nations pamphlets to describe how different types of illegal drugs, including the highly addictive methamphetamine, or “shabu”, could trigger aggressive behavior among users.

“I do not deny that there were people killed in that campaign,” he added. “But why were they killed? Because a ‘shabu’ user, a lieutenant of the ‘shabu’ syndicate, always has a gun and this was my experience when I was mayor. They always fight it out.”

During his 22 years as mayor of the southern city of Davao, Duterte estimated 600 drug suspects had been killed in police encounters.

His anti-narcotics crackdown has come under unprecedented scrutiny following the high-profile Aug. 16 killing of a 17-year-old student, among the 90 people killed in less than a week of intensified police raids.

A recent poll showed fewer Filipinos believe the official stance of the Philippine National Police that those killed in anti-drugs operations had refused to go quietly.

“When I say, ‘I will kill you if you destroy my country,’ and ‘I will kill you if you destroy the young of my country,’ I am asking everybody to find me a fault in those two statements,” Duterte told the audience.