Philippine President Rodrigo Duterte called Barack Obama a “son of a whore” on Monday as he vowed not to be lectured by the US leader on human rights when they meet in laos. The acid-tongued Duterte bristled at warnings he would face questioning by the US President over a crime war in the Philippines that has claimed more than 2,400 lives in just over two months. “You must be respectful. Don’t just throw away questions. Son of a whore, I will curse you in that forum,” Duterte told shortly before flying to laos.