The comments by Duterte are the latest in a series of diplomatic rows which have prompted Washington to summon Manila’s envoy to complain.

“As you know, I’m fighting with (US Secretary of State John Kerry’s) ambassador. His gay ambassador, the son of a whore. He pissed me off,” Duterte said on Friday.

Winning a landslide presidential victory in May, Duterte often gleefully uses foul and incendiary language. Duterte first came into conflict with Goldberg after saying that he wanted to rape a “beautiful” Australian missionary who was sexually assaulted and murdered in a 1989 prison riot in Davao.

Despite often using homophobic language, Duterte has also condemned discrimination against LGBT in the Philippines and has said that he would consider legalising same-sex marriage.