United States President Donald Trump pledged to "get to the bottom" of the case of missing Saudi journalist Jamal Khashoggi.
Trump told reporters he had talked to the Saudi authorities "at the highest level" about Khashoggi.
Khashoggi, a US resident and critic of the Saudi monarchy, entered the Saudi consulate in Istanbul on 2 October and has not been seen since.
Turkish authorities say Khashoggi was killed. Saudi Arabia denies this.
"We cannot let this happen to reporters, to anybody," Trump said on Wednesday.
"We're demanding everything. We want to see what's going on there."
The White House said Secretary of State Mike Pompeo and senior officials had spoken to Saudi Crown Prince Mohammed Bin Salman on Tuesday and asked for more details about the situation.