Donald Trump dispatched his top diplomat to Saudi Arabia to “get to the bottom” of the disappearance of dissident Jamal Khashoggi even as the US president signalled he was prepared to accept the kingdom’s denials of responsibility.

Mr Trump’s move to send Mike Pompeo, US secretary of state, to Riyadh came as the Khashoggi case threatened to isolate Riyadh internationally. Some of Wall Street’s highest-profile financiers, including Blackstone chief Stephen Schwarzman, have withdrawn from a major Saudi conference.