After emerging from the White House meeting, Pompeo told reporters he stressed to both Turkish and Saudi officials that the Trump administration is taking the Khashoggi case "very seriously." He also said Trump has agreed to give authorities time to complete their investigations.
"I told President Trump this morning that we ought to give them a few more days to complete that so we can get a complete understanding the facts surrounding that, at which point we can make a decision about how the United States should respond to the issues surrounding Mr. Khashoggi," Pompeo said.
"They also made clear that [Saudi Arabia] will conduct a complete, thorough investigation of all of the facts surrounding Mr. Khashoggi, and that they will do so in a timely fashion," he said. "And that this report itself will be transparent, for everyone to see, to ask questions about."
Khashoggi has not been seen for more than two weeks. He went to the Saudi consulate in Istanbul, Turkey, on Oct. 2 to pick up documents needed for his planned wedding. Some authorities believe he was killed in the consulate, possibly on orders from Riyadh.
A possible reason for the killing is Khashoggi's work as a U.S.-based journalist for The Washington Post. The Saudi writer was often critical of the Saudi government, King Salman and Crown Prince Mohammed bin Salman.
Pompeo emphasized Thursday that the United States has a "long, strategic relationship" with Saudi Arabia the administration needs to be mindful of.
"They can be an important counterterrorism partner, they have custody of two holy sites, they are an important strategic alliance," he said.
The State Department chief also said Turkey is conducting its own investigation and believes the administration will soon get a "complete picture" of what happened to Khashoggi.
"We're all going to get to see the response from Saudi Arabia to this," Pompeo said. "When we see that, we'll get a chance to determine -- all of us will get a chance to make a determination -- as to the credibility of the work that went into that, whether it's truly accurate, fair, and transparent in the very way they made a personal commitment to me."
Turkish officials have said they have audio and video evidence Khashoggi was killed inside the consulate.
As the Khashoggi mystery deepened, many businesses and investors from around the world have said they will boycott an investment conference next week. U.S. Treasury Secretary Steven Mnuchin said Thursday he won't attend.
International Monetary Fund Director Christine Lagarde, JP Morgan Chase CEO Jamie Dimon, Blackstone chief Stephen Schwarzman and the heads from Uber, BlackRock, MasterCard and Viacom have all said they won't attend due to the Khashoggi case.
Earlier Thursday, the Post published what may have been Khashoggi's final column, which called for a free press throughout the Arab world.
"The Arab world needs a modern version of the old transnational media so citizens can be informed about global events," Khashoggi wrote. "More important, we need to provide a platform for Arab voices.
"We suffer from poverty, mismanagement and poor education. Through the creation of an independent international forum, isolated from the influence of nationalist governments spreading hate through propaganda, ordinary people in the Arab world would be able to address the structural problems their societies face."
Karen Attiah, global opinions editor of the Post, said she received Khashoggi's column the day after his disappearance but held on to it in hopes he would return so they could edit it together.
"Now I have to accept: That is not going to happen," Attiah wrote.
CNN reported Wednesday that some of the suspects in the case have ties to the Saudi crown prince's inner circle. Turkish officials told the network they were led by a Saudi intelligence officer who's close to the prince's confidants.
The New York Times hinted at the same connection Thursday, writing that U.S. intelligence officials are viewing increasing circumstantial evidence that connects the prince with Khashoggi's disappearance.
Pompeo visited the Saudi royal family and Turkish officials on Tuesday and Wednesday to learn more about Khashoggi. Trump said he wants to know more about the audio and video evidence Turkey says it has.
"I'm not sure yet that it exists, probably does, possibly does," Trump said.
Trump also denied he gave Saudi Arabia "cover" by previously suggesting Khashoggi's death could have been carried out by "rogue killers," and not challenging the royal family's denials.