President Donald Trump declared the US will uncover the truth about what happened to journalist and US resident Jamal Khashoggi, whose possible murder at Saudi hands after disappearing in Istanbul has captured worldwide attention. Trump promised to personally call Saudi Arabia's King Salman soon about “the terrible situation in Turkey”.

“We’re going to find out what happened,” Trump pledged on Friday when questioned by reporters in Cincinnati where he was headlining a political rally.

Khashoggi, a forceful critic of the Saudi government, went missing more than a week ago after entering a Saudi consulate in Istanbul, and Turkish officials have said they believe he was murdered there. US officials say they are seeking answers from the Saudi government and are not yet accepting the Turkish government’s conclusions.

The Saudis have called accusations that they are responsible for Khashoggi’s disappearance “baseless”. Widely broadcast video shows the 59-year-old writer and Washington Post contributor entering the consulate on Tuesday of last week, but there is none showing him leaving.

Jamal Khashoggi. Agencies

Separately, Secretary of State Mike Pompeo spoke to Khashoggi’s fiancee, Hatice Cengiz, who accompanied him to the Saudi consulate, the State Department said on Friday. No details of the conversation were released.

In an interview on Friday with The Associated Press, Cengiz said Khashoggi was not nervous when he entered the consulate to obtain paperwork required for their marriage.

“He said, ‘See you later my darling,’ and went in,” she told AP.

Citing anonymous sources, the Post reported on Friday that Turkey’s government has told US officials it has audio and video proof that Khashoggi was killed and dismembered. AP has not been able to confirm that report. In written responses to questions by AP, Cengiz said Turkish authorities had not told her about any recordings and Khashoggi was officially “still missing”.