In that same speech last week he warned a UN official that he'd slap her if she investigated the drug killings in his country - but then in the next breath offered to host an international conference on human rights.
Duterte does have at least one fan - you guessed it: the man who has himself made many weird and wacky statements in his time, Donald Trump, who met with him in Manila the other night.
As a major protest was being staged in the city, depicting Trump with four arms, bent to form a swastika, the pair were having a yarn, not about human rights but about their mutual dislike of Barack Obama. Indeed Trump praised his fellow president for his crackdown on drugs saying he's doing an incredible job.
So while Ardern didn't get to meet with Trump, barely exchanging a hello, but observing him as he on a few occasions spoke to a group she was part of, she did get to meet Duterte.
It didn't get off to a great start though with the President saying he was told he had to see her, mentioning the large number of leaders he had to meet along the way.
He then babbled on, regaling her with disjointed and often difficult to fathom tales, including the time a person travelling with him was stopped by New Zealand Customs for trying to bring in a fish.
It's likely then that when she did raise the human rights issue she'd probably get the same treatment he meted out to the dominant Catholic Church in his country, telling them not to f**k with him.