Philippines' President Rodrigo Duterte addressing soldiers during a visit in Butig, Lanao del Sur, southern Philippines Nov. 30, 2016. Reuters

Rodrigo Duterte offered his latest controversial remarks on Thursday. This time they were aimed at the United Nations’ human rights chief. The Philippines president attacked the U.N.'s high commissioner for human rights for suggesting the organization should open a murder investigation against Duterte, describing Zeid Ra'ad al-Hussein as an "idiot" and claiming he'd "burn down the United Nations."

Duterte, who became president of the Philippines in June 2016, has repeatedly shared detailed accounts of killings against suspected drug dealers and criminals he committed on the streets of Davao, when he was mayor of the city. "In Davao, I used to do it personally, just to show the guys that if I can do it, why can’t you?" Duterte said earlier in December. His recent comments followed a statement from the United Nation’s high commissioner for human rights, who condemned the Duterte's remarks, which appeared to openly boast about killing civilians of the Philippines in the street.

Philippine President Rodrigo Duterte pointing to a piece of paper containing a list of personalities he alleged are involved with the drug trade, as he delivered a speech during an awarding ceremony for outstanding Filipinos and organizations overseas, at the Malacanang Palace in Manila, Philippines Dec. 19, 2016. Reuters

"It is unthinkable for any functioning judicial system not to launch investigative and judicial proceedings when someone has openly admitted being a killer," al-Hussein said in his statement.

"You do not talk to me like that, you son of a bitch," the president responded, speaking at an army base in the southern city of Zamboanga Sunday. "I will burn down the United Nations if you want. I will burn it down if I go to America." The president has also encouraged vigilante-styled killings of anyone openly breaking the law in the Philippines as part of his crackdown on drugs and crime throughout the country.

"Your understanding of international law is lacking," Duterte continued. "We are the ones contributing to the United Nations. You morons! You sons of whores! And I pay your salaries. Do not open your mouth there. I employ you."

The Philippines' "war on drugs" has been linked to more than 5,900 deaths since Duterte took office in June. Of those killings, 2,086 were part of police operations, while 3,841 were extrajudicial or vigilante-style killings, CNN reported. The killings, as well as Duterte’s controversial remarks, have sparked international outcry since he became president in June.

The U.S. Senate Foreign Relations Committee recently called Duterte’s "war on drugs" into question in a letter sent to the department on Thursday, describing the president’s efforts "a campaign of mass atrocities thinly disguised as a response to a public health emergency."

"Rather than address the systemic problems related to the country’s drug crisis, invest in treatment programs, or approach the epidemic with a focus on the health and well-being of the Philippine people," the letter, signed by Republican Sen. Marco Rubio, and two Democratic senators, Sen. Markey and Sen. Coons, said. "President Duterte has instead pledged to kill another 20,000 to 30,000 people, many simply because they suffer from a drug use disorder."