U.S. Secretary of State Mike Pompeo is in Saudi Arabia to speak to its king over the disappearance and alleged killing of Saudi writer Jamal Khashoggi.
U.S. President Donald Trump dispatched Pompeo to the kingdom after he spoke with the king of Saudi Arabia about Khashoggi's disappearace.
Trump said King Salman denied "any knowledge of whatever may have happened" to Khashoggi, who wrote critically of Saudi Crown Prince Muhammad bin Salman.
Pompeo is also due to hold talks with the Saudi crown prince, an unnamed U.S. official said.
Meanwhile, a Turkish police forensics team wrapped up its search of the Saudi Consulate in Istanbul early on October 16.
UN human rights chief Michelle Bachelet on October 16 called on Saudi Arabia and Turkey to reveal all they know about Khashoggi's disappearance and said the immunity which diplomatic premises enjoy should be lifted immediately in the Khashoggi case.
"Immunity should not be used to impede investigations into what happened and who is responsible," Bachelet aid in a statement.
"Given there seems to be clear evidence that Mr. Khashoggi entered the consulate and has never been seen since, the onus is on the Saudi authorities to reveal what happened to him from that point onwards."
Pompeo will stop in Turkey after his trip to Saudi Arabia, a National Security Council spokesman said.
Khashoggi disappeared on a visit to the consulate two weeks ago. Turkish officials fear he was killed and dismembered. Saudi Arabia has dismissed those allegations as "baseless," but has been unable to explain what happened to him.
Trump had said Saudi Arabia would face “severe punishment” if it was involved in the disappearance and suspected killing of Khashoggi.
Unconfirmed reports overnight by U.S. media suggest Saudi Arabia soon may concede Khashoggi was killed at the consulate in an interrogation.
Global concerns about Khashoggi's fate have contributed to a fall of share prices in the Saudi stock market.
Europe’s largest economies -- Britain, France, and Germany -- said on October 14 that they were treating the case with “the utmost seriousness.”
Several media organizations and Western business executives have pulled out of a Riyadh investment conference scheduled for next week.