MANILA - President Rodrigo Duterte on Tuesday said he agrees with former Environment Secretary Gina Lopez that open pit mining in the country should stop.

"Tama si Gina. Yesterday, I asked General Cimatu, Secretary of DENR (Department of Environment and Natural Resources), to look into the eventual closing of open pit mining. I agree with Gina Lopez that this has to stop sometime," Duterte told reporters in a chance interview at a hotel in Taguig City.

The President had earlier warned the mining industry to "restore the virginity" of mining areas or "I will tax you to death."

Lopez, whose appointment to the environment post was rejected by lawmakers amid strong opposition from the mining industry, said Monday that open-pit mining would be a "financial liability" to the government.

This as an inter-agency council studied the lifting of a ban she had put in place against the practice.

• READ: MGB mulls lifting of ban on open-pit mining

Lopez added that when a company halts operations, its open pit would be filled with water, which would later turn toxic.

"We’d have to detox that open pit water forever. Who is going to do that? The government? Each open pit is a financial liability to government for life because no matter if the mining company commits to take care of that open pit, will they take care of it forever?," she told reporters.

"It is a financial liability for life, and is it right that our taxpayers' money, meant for our people, for food, for education, for our people, be used to address open pit? But if the mining company goes, what choice do we have?" she added.

Before she stepped down in May, Lopez ordered several mines shut and suspended and threatened to cancel other contracts.

Lopez said mining sometimes works to the "detriment" of host communities.

"The existence of open pits destroy the economic potential of the place. It destroys it. Once you put it there, what can you do there? Can you invest there?" she said.

"The existence of open pits violates the constitutional rights of our people to a clean and healthy environment… For whatever law or whatever legal thing they say, it is a violation of our constitutional rights," she added.