Philippines police on Monday said that the number of drug-related deaths have doubled to about 1,800 since President Rodrigo Duterte assumed office in June, even as he threatened on Sunday to pull out of the United Nations (UN) and invite China and others to form a new organisation.

He made these comments in response to two United Nations human rights experts, slamming the newly formed government for encouraging extra-judicial killings to eradicate the drug menace in the Philippines.

Duterte's comments

"I will prove to the world that you are a very stupid expert. I do not want to insult you. But maybe we'll just have to decide to separate from the United Nations. Why do you have to listen to this stupid?" said President Duterte, in a middle-of-the-night news conference, in his home town, Davao, as he urged his critics to count not just the number of drug-related deaths, but also the innocent lives lost to drugs.

He continued criticizing the United Nations saying it was not able to fulfil its own mandate, but was instead "worrying about the bones of criminals piling up."

"You know United Nations, if you can say one bad thing about me, I can give you 10 [about you]. I tell you, you are inutile. Because if you are really true to your mandate, you could have stopped all these wars and killing," Duterte said, while alluding to the UN's inability to address hunger and terrorism and wars in Syria and Iraq.

Asked about the possible consequences of his comments, he said: "What is repercussions? I don't give a shit to them." He added that the United Nations should have sent someone such as a rapporteur to hold discussions with him.

"You do not just go out and give a shitting statement against a country," Duterte, also known as "The Punisher," was quoted saying.

Extra-judicial killings promoted by Philippines government?

During a  Senate committee investigation on extra-judicial killings on Monday, Ronald Dela Rosa, Philippine National Police Chief disclosed that 712 drug traffickers and users had been killed during police operations, while adding that police were also investigating 1,067 drug-related killings outside normal police work.

Duterte has granted police immunity and imposed 'shoot to kill' orders against organised criminals and those who resist arrest.

As of Aug. 15, at least 130 bodies of drug pushers were yet to be identified. Though the encounters involved police and security personnel, many have reportedly occurred due to vigilante citizens, whom Duterte has been encouraging before being inducted into office.

In an election campaign speech broadcast on national television on June 5, Duterte encouraged citizens to kill suspected drug dealers or users as a "duty," and offered huge bounties to people who turn in drug dealers – "dead or alive."

"Double your efforts. Triple them. We will not stop until the last drug lord, last financier and last pusher has surrendered or put behind bars or below the ground. If you know of any addicts, go ahead and kill them yourself," President Duterte said in his inauguration speech as he addressed the nation on June 30.