MANILA - President Rodrigo Duterte may soon name more "persons of interest" possibly involved in the drug trade, Malacañang said Sunday.

"In time, sigurado po ako, i-announce din po ng President 'yung iba pang mga suspek, 'yung iba pang mga persons of interest," Presidential Communications Office Secretary Martin Andanar told state-run radio dzRB.

Andanar said a matrix from the Philippine Drug Enforcement Agency (PDEA) shows that at least 1.8 million people are connected to the drug menace.

"If you see the matrix, you'll probably say that it is really unbelievable that ganoon kadami na 'yung mga involved at masusuka ka 'pag makikita mo," he said.

The Palace official also denied Duterte's anti-narcotics efforts only target poor drug peddlers while big-time drug lords remain scot-free.

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He noted that the President recently named "Level 5" drug lords, who are "the highest that you can get in the hierarchy of those who are selling, pushing, peddling illegal drugs."

"Now, as far as I can remember in the history, I have not seen a president who has been so brave in announcing to the public the people who have been or allegedly are behind this menace of drugs," Andanar added.

Duterte recently identified alleged drug bigwigs Peter Lim, Peter Co and Herbert Colangco.

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The President on Friday met with Lim at the Philippine Drug Enforcement Agency (PDEA) Region 11 office in Davao City.

He advised the Cebuano-Chinese businessman to go to the National Bureau of Investigation (NBI) to clear his name and talk with Justice Secretary Vitaliano Aguirre III.

"We want to help you. Help us clear you," he said. "We're not here to pin down innocent citizens."

Andanar defended Duterte's move to meet with Lim despite the President's earlier pronouncement that the alleged drug lord "will die" if he sets foot in the country.

"The alleged suspect, drug lord suspect, Peter Lim has already expressed his intentions to clear his name. Let's leave it at that," he said.

Andanar said he was not aware if the President is planning to meet other alleged drug personalities.