Under pressure from Catholic leaders to put an end to a spate of extrajudicial killings against suspected drug criminals, Philippine President Rodrigo Duterte insisted that priests and bishops should “use shabu,” the local name for crystal methamphetamine, to “understand” how devastating it is to communities.

“The church really doesn’t understand,” Duterte said during a speech at an event commemorating the anniversary of a local medical center in northern Nueva Ecija province. “They know [the drug problem], they know that it is worst, and yet they say ‘extrajudicial killing,'” he told the audience, with a wag of the finger meant to symbolize the church’s disapproval.

“When a person is high, they really put up a fight. So some priests should take shabu so they understand,” Duterte recommended. “I recommend one or two of the bishops [do it], too.”

“What is really raging in my heart is that you [drug traffickers] are making so many slaves, millions of them, in my country. I could not accept that,” Duterte told the audience. “Honestly, I could not allow that. They are slaves to a chemical and making the people very rich.”

“The killing? It will not stop,” he promised.

Duterte also challenged priests on their piety. “We’re the same, with two, three wives. Don’t get me started – all the hypocrisy,” Duterte lamented, alluding to his own multiple marriages.

The challenge to priests to use methamphetamine, a highly dangerous drug, comes at an unusually friendly moment in relations between the Philippine head of state and the Catholic church. While Duterte himself is Catholic, as is more than 80 percent of his country, he has long been at odds with the Vatican. As a candidate, he prompted criticism for calling Pope Francis the “son of a whore” in a rant about Manila’s traffic woes during the pontiff’s 2015 visit. Duterte subsequently promised to visit the Vatican and personally apologize for the remarks.

This week, however, Pope Francis blessed Duterte from afar, receiving envoy Presidential Adviser on the Peace Process Jesus Dureza and blessing the nation of the Philippines before the Vatican moderates peace talks with radical leftist groups in the country. Dureza handed Pope Francis a letter from Duterte, whose contents were private, except for the first page, which conveyed a message of “profound respect.”

Duterte’s call for clergy to use illegal drugs closely followed the exchange with Pope Francis.

Priests in the Philippines have begun to loudly protest Duterte’s policies against drug traffickers. “Moral norms are being violated and so now is the time for the Church to speak up,” Jerome Secillano, public affairs chief for the Catholic Bishops Conference of the Philippines, said this week. Another bishop, Teodoro Bacani, referred to the drug war as a “bringer of death.”

Duterte won the presidency on a campaign promise to eradicate drug abuse from the Philippines, particularly targeting the use of “shabu.”

In 2015, government estimates put the availability of shabu at 90 percent of neighborhoods in Manila, according to a Vice report from that year. Manila estimates that up to four million people are addicted to drugs or involved in the drug trade nationwide.

According to the U.S. National Institute of Drug Abuse, use of methamphetamine can trigger “a number of psychotic features, including paranoia, visual and auditory hallucinations, and delusions” that can last for “months” after quitting the drug. The drug also causes “severe structural and functional changes in areas of the brain associated with emotion and memory,” and withdrawal from “shabu” can also trigger violent, erratic behavior.

As of January, the Philippine government estimates that more than 6,000 people have been killed in relation to anti-drug operations since Duterte took office, and more than 60 percent of these died as a result of an extrajudicial killing. An excess of one million people have surrendered to police to avoid being killed, and nearly 900 kilograms of “shabu” have been seized in police raids.