Philippines President Rodrigo Duterte threatens to leave UN after it criticised his war on drugs

Philippines President Rodrigo Duterte has threatened to leave the United Nations after it criticised a spate of killings carried out as part of Duterte's war on drugs.

The president, who has sanctioned the killings of traffickers in an effort to crack down on the drugs trade, said he might ask China and African nations to form another international body.

Around 900 suspected drug traffickers have been killed since Duterte came to power after a landslide victory in the May 9 election.

UN human rights experts have said that the president's directive for police and members of the public to kill suspected drug traffickers amounts to "incitement to violence and killing - a crime under international law".

Duterte, however, denied that the government was responsible, and dismissed the UN experts as "stupid".

"I do not want to insult you but maybe we'll just have to decide to separate from the United Nations," he said.

"If you are that rude, we might just as well leave. So take us out of your organisation. You have done nothing. Where were you here the last time? Never. Except to criticise."

Duterte said the UN had been unable to tackle hunger and terrorism, and called on the body to refund its contribution "so we can go out".

The president has gained infamy for his controversial comments and tough approach on crime. Duterte's style earned him the nickname "The Punisher" during his 22 years as mayor of the Philippines' third biggest city Davao.