US has demanded answers from Saudi Arabia on missing journalist: Trump

US President Donald Trump said Wednesday that he has taken up the case of missing journalist Jamal Khashoggi with Saudi authorities "at the highest level" and demanded answers from them over the mysterious disappearance of the Washington Post contributor.

Khashoggi, a US resident, vanished on October 2 after entering the Saudi consulate in Istanbul. Turkish authorities suspect he was abducted and murdered by the Saudis.

But Riyadh insisted the 59-year-old journalist had left the building and that murder claims are "baseless".

"This is a bad situation. We cannot let this happen. To reporters and to anybody, we cannot let this happen. We are going to to the bottom (of it), Trump told reporters at the White House.

Trump said he has taken up this matter with the Saudi Arabia at the highest level. Let me say this, the highest level, he said in response to a question adding that this is a very serious situation.

Turkish investigators are examining CCTV footage showing the moment the journalist entered the kingdom's consulate in Istanbul to obtain documents ahead of his marriage to his Turkish fiance Hatice Cengiz.

Trump said he and the First Lady have received a letter from the fiance of the journalist.

We are in contact with her now. And we want to bring her to the White House. It's very sad situation. It's a very bad situation. And we want to get to the bottom of it, he said.

Meanwhile, White House National Security Advisor, John Bolton and White House Senior Advisor, Jared Kushner spoke to Saudi Arabian Crown Prince Mohammed Bin Salman Tuesday about the missing Washington Post journalist.

Secretary of State Mike Pompeo had a follow up call with the Crown Prince to reiterate the United States request for information.

In both calls they asked for more details and for the Saudi government to be transparent in the investigation process. We will continue to monitor this situation and provide updates as available, White House Press Secretary Sarah Sanders said.

Later, at another White House event, Trump expressed his disappointment over the current situation.

"We are going to have comment on that soon. We are very disappointed to see what is going on. Don't like it. Don't like it at all. And are going to get to the bottom of it, Trump told reporters in response to a question.