Philippines President Rodrigo Duterte admits he underestimated the drug problem and reiterated orders for law enforcement to “destroy” criminals dealing narcotics.

Speaking at the opening of a solar energy facility on Wednesday, Duterte said he made a mistake in promising during his election campaign that he could eradicate drugs within a matter of months.

The president, who has outraged human rights groups over extrajudicial deaths during his one year in office, said the recent killing of a student by police was “really bad” and will be investigated.

READ MORE: Duterte tells critics he’d be ‘happy to slaughter’ drug addicts like Hitler massacred Jews

Kian Delos Santos was killed during a police raid in Caloocan City on August 18.

Two autopsies with contradicting reports have been carried out on the 17 year old’s body, with one examination suggesting the student may have been shot at close range in the head, execution style, reports Inquirer.net.

Police claim the teenager was killed during a shootout.

Despite a spate of deaths at the hands of security forces since his tenure began, Duterte suggested the war on drugs must continue for the good of the upcoming generation.

“If I do not get rid of drugs then I will compromise the next generation. I have a duty to destroy it [drug crime]. My orders to the military and the police was not to just go into one or two operations,” he told delegates on Wednesday.

“I ordered them to destroy the apparatus of a drug organization,” he said. “And if to destroy, the police and military destroy you, that’s your problem.”

However, the Philippines leader said authorities are not permitted to “kill a person that is kneeling down begging for his life.”

“That is murder,” he said.

Duterte also denied that he promised to protect police who commit abuses.

Duterte threatens to unleash the full might of the military against drug lord politicians https://t.co/AOt2kc78pc — RT (@RT_com) August 9, 2017

“Let us be clear on this. I said I would protect those who are doing their duty. I never promised to protect those who are supposedly doing their duty but committing a crime in the process.”

Since coming to power, Duterte has issued a number of statements regarding violent intent towards suspected drug criminals.

Last year, the Philippines leader said he he would be "happy" to slaughter 3 million drug addicts.

Amnesty International has described Duterte’s anti-drugs campaign as a “murderous war on the poor.”

In January, the human rights organization estimated that around 2,500 alleged drug dealers had been killed by law enforcement.