The US government on Monday summoned the charge d'affaires of the Philippine Embassy to clarify what it called "inappropriate comments" made by Philippine President Rodrigo Duterte about US Ambassador Philip Goldberg.

"We've seen those inappropriate comments made about (US)Ambassador (Philip) Goldberg. He's a multi-time ambassador, one of our most senior diplomats," US State Department spokeswoman Elizabeth Trudeau told a news briefing.

But She declined to disclose the details of the conversation that US officials held with Patrick Chuasoto, the charge d'affaires of the Philippine Embassy in Washington.

"I'm not going to read out that detailed conversation, but it was specifically on those remarks," Trudeau said.

Duterte reportedly called Goldberg a "gay ambassador" and "son of a bitch" during a recent meeting with soldiers.

"I am pissed with him. He meddled during the election, giving statements here and there. He was not supposed to do that," Duterte was quoted as saying on the occasion.

Goldberg told the US media in April that the United States did not condone anyone who either degrades women or trivializes issues as serious as rape, referring to the joke made by Duterte during his campaign about the rape and murder case involving Australian missionary Jacqueline Hamill in 1989.