Turkish authorities have claimed that Jamal Khashoggi has been killed.
The New York Times and the Washington Post have reported, citing anonymous sources, that Saudi officials may soon acknowledge Khashoggi's slaying at the consulate but blame it on a botched intelligence operation.
"I am immediately sending our Secretary of State to meet with King!"
Saudi journalist Jamal Khashoggi, a columnist for The Washington Post newspaper, who apparently went missing after going to the Saudi Consulate in Istanbul.
Police planned a second search at the Saudi consul's home nearby. The official, who spoke on condition of anonymity in line with government regulations, gave no timeline for the search.
Worldwide leaders and business executives are severing or rethinking ties to the Saudi government after Khashoggi's high-profile disappearance.
Members of the US Congress, including some of Trump's fellow Republicans, are among the loudest voices in the United States demanding answers and action on Khashoggi, who moved to Washington a year ago fearing retribution for his criticism of the crown prince. The Turkish official would not comment on the disposal method for the body. Khashoggi fled Saudi Arabia and took up a self-imposed exile in the United States after the prince's rise, and had written columns critical of his policies.
Yet another suspect, Salah al-Tubaigy, works as the head of Saudi Arabia's Scientific Council of Forensics and specialises in mobile autopsies. The king greeted Pompeo by saying: "I hope you are comfortable here".
Saudi officials have been in and out of the building since Khashoggi's disappearance without being stopped. Turkey fears Khashoggi was killed and dismembered at the consulate.
"I think we have to find out what happened first", Trump said.
Meanwhile, Turkish forensic investigators overnight searched the Saudi Consulate in Istanbul, where Khashoggi disappeared October 2. They put the president at odds with other key allies and with some leaders in his Republican Party who have condemned the Saudi leadership for what they say is an obvious role in the case.
In Riyadh, Saudi Foreign Minister Adel al-Jubeir greeted Pompeo at the airport.
Lagarde had been set to participate in the kingdom's Future Investment Initiative conference that has been boycotted by global business and media leaders since the suspected death of Jamal Khashoggi, who was last seen at the Saudi consulate in Istanbul on October 2.
Turkish officials say they fear a Saudi hit team killed Khashoggi, who has been missing almost two weeks. Saudi officials previously have called the allegations "baseless", but reports in USA media on Tuesday suggested the kingdom may acknowledge the writer was killed there.
Trump wrote, "He was with Secretary of State Mike Pompeo during the call, and told me that he has already started, and will rapidly expand, a full and complete investigation into this matter". Saudi Arabia has called those allegations "baseless", but has been unable to explain what happened to him. On Monday, sources told CNN that the report will acknowledge that Khashoggi died in a botched interrogation, one that was meant to lead to his abduction from Turkey.