Journalist Khashoggi's death was 'a plot gone awry': Trump

US President Donald Trump has said the death of dissident journalist Jamal Khashoggi was the result of "a plot gone awry".

He also said Monday that the Saudi Crown Prince Mohammed bin Salman has told him that neither he nor the king were involved in this.

He (Crown Prince) says he is not involved nor is the king, Trump told USA Today, a popular American daily, in an interview.

If their involvement was proven, I would be very upset about it. We'll have to see, the president said.

Trump, who has said he wants to get to the bottom of the case told the daily that he still believed it was a plot gone awry.

He reiterated that he would oppose efforts to cease arms sales to the kingdom in response.

"In characterising the Khashoggi incident as a 'plot gone awry', Trump indicated that he thought the journalist was not deliberately lured into the consulate to be murdered, the daily reported after the interview.

Over the past few days, Trump has spoken with the Saudi prince and Turkish President Tayyip Erdogan.

More details of the incident would be known in a day or two, the US president said.