President Rodrigo Duterte acknowledged on Monday illegal drug activities increased after he removed the Philippine National Police (PNP) as the main agency in his campaign against illegal drugs.

In an ambush interview in Malacanang, Duterte said he needs men whom he can trust to handle the war on drugs.

"There is again a rise of the drug activities by 20 percent," Duterte said without elaborating.

Duterte stripped off the PNP of its authority to lead the campaign against illegal drugs through "tokhang" last month after some policemen allegedly became involved in the murder of a South Korean businessman.

These police "tokhang" in victimizing Jee Ick-joo, who was allegedly killed inside police Camp Crame headquarters after his family paid ransom.

Amnesty International was able to interview policemen who allegedly admitted that they were paid to kill drug suspects.

Before he returns the job to the PNP, Duterte said, "(PNP chief Director General Ronald) Dela Rosa’s job is to look for young men in the PNP who are imbued with patriotic fervor to serve their country."

The Philippine Drug Enforcement Agency is the lead agency in the government's drug war.

Since the PDEA took over the job, the number of drug suspects who have been killed reportedly declined.

When the PNP was still handling the "tokhang" campaign, the number of drug suspects killed reached to about 7,000. But the number included those who were not killed under police operation.

Recently, retired police officer Arthur Lascanas retracted his initial statement and pointed to Duterte as the one ordering killings in Davao City when he was its mayor through the Davao Death Squad.

Duterte admitted he knew Lascanas. "Well, as a policeman, yes. I saw him once, twice a year," he said.

Asked on Lascanas' claim Duterte created a task force in Davao which eventually became the Davao Death Squad, the president said he is not engaged in any favoritism among the police and the military.

But Duterte said he did not deny many criminals died in Davao .

"I did not deny that hundreds of criminals died in Davao City . In my 23 years (as mayor)? They're all gone," he said.

"But, you know, I’m an employee of the government, I built a city and I will build a nation...do not destroy my country, do not deprive us of our young people. You will die." Celerina Monte/DMS