MANILA (UPDATE) - President Rodrigo Duterte on Tuesday said Naga City was once a hotbed of shabu, as he belittled anew the leadership qualities of Vice President Leni Robredo.

Duterte said he does not think Robredo “can improve on anything here”, which is why he would not suggest a "constitutional succession" in case the military decides to oust him.

The President then cited how Naga, Robredo's bailiwick, was supposedly a hotbed of shabu (methamphetamine hydrochloride), the drug of choice for many Filipinos.

“Of course she will deny it,” Duterte said.

This is not the first time the President tagged a Philippine city of being a hotbed of illegal drugs.

Duterte once called Iloilo as the “most shabulized” area in the Philippines.

Last month, Duterte also chided Robredo, saying the vice-president was “incompetent.”

Robredo, a lawyer and a former lawmaker, in response said Duterte should instead focus on economic issues rather than insult her or God, as the country’s economy continued to falter due to the quickening inflation.