The United States received a payment of US$100 million ($152m) from Saudi Arabia yesterday, the same day Secretary of State Mike Pompeo arrived in Riyadh to discuss the disappearance of journalist Jamal Khashoggi, a State Department official confirmed today amid global calls for answers in the case.

Saudi Arabia publicly pledged the payment to support US stabilisation efforts in northeastern Syria in August, but questions persisted about when and if Saudi officials would come through with the money.

The timing of the transfer, first reported by the New York Times, raised questions about a potential payoff as Riyadh seeks to manage the blowback over allegations that Saudi agents were responsible for Khashoggi's disappearance.

The State Department denied any connection between the payment and Pompeo's discussions with Saudi officials about Khashoggi, a Washington Post contributing columnist.

"We always expected the contribution to be finalised in the [northern autumn] time frame," Brett McGurk, the State Department's envoy to the anti-Islamic State coalition, said. "The specific transfer of funds has been long in process and has nothing to do with other events or the secretary's visit."

Saudi Arabia, an oil rich monarchy and staunch US ally, has long relied on its financial largesse to persuade partners to support its foreign policy objectives.

Western diplomats suspect that the kingdom will also compensate Turkey for its willingness to launch a joint investigation on Khashoggi's disappearance - a payback that could come in the form of large-scale debt relief, strategic buyouts or other arrangements that boost Turkey's ailing economy.

Khashoggi's disappearance has hurt the reputation of Saudi Arabia's crown prince, Mohammed bin Salman, whose close relationship with US President Donald Trump's son-in-law and senior adviser Jared Kushner has put him at the centre of the Administration's Middle East policy.

Turkish authorities say Khashoggi was killed on October 2 during a visit to the Saudi consulate in Istanbul to obtain a document required to get married.

Trump initially promised "severe punishment" for Saudi Arabia if the United States determined that Saudi agents killed Khashoggi. But the President has since floated an alternative theory involving "rogue killers" and compared the case to the sexual assault allegations against recently confirmed Supreme Court Justice Brett Kavanaugh.