Iranian President Hassan Rouhani said that Saudi Arabia would not have murdered Jamal Khashoggi without American protection, according to IRNA. Picture: Reuters/Brendan Mcdermid

Geneva - Iranian President Hassan Rouhani said on Wednesday that Saudi Arabia would not have murdered prominent journalist Jamal Khashoggi without American protection, according to the Islamic Republic News Agency (IRNA).

President Donald Trump said on Tuesday Saudi authorities staged the “worst cover-up ever” in the killing of Khashoggi in Turkey this month, as the United States vowed to revoke the visas of some of those believed to be responsible.

Meanwhile, President Tayyip Erdogan said on Wednesday Turkey will not allow those responsible for the killing of Saudi journalist Jamal Khashoggi to avoid justice, from those who ordered it to those who carried it out.

"We are determined not to allow a cover-up of this murder and to make sure all those responsible - from those who ordered it to those who carried it out - will not be allowed to avoid justice," Erdogan said at a speech in Ankara.

He said some people had been uncomfortable with him sharing evidence regarding the investigation into the killing in his speech on Tuesday.