President Trump said Monday that he is “concerned” about missing columnist and Saudi government critic Jamal Khashoggi, and Secretary of State Mike Pompeo asked ally Saudi Arabia to provide answers about his disappearance.

The president was asked about the case as he returned to the White House after a speech in Florida.

“I am concerned about it,” Trump said. “I don’t like hearing about it. Hopefully that will sort itself out. Right now nobody knows anything about it, but there’s some pretty bad stories going around. I do not like it.”

Vice President Pence tweeted Monday night that he was “deeply troubled” to hear reports of Khashoggi’s disappearance.

“If true, this is a tragic day. Violence against journalists across the globe is a threat to freedom of the press & human rights. The free world deserves answers,” Pence said in the tweet.

Late Monday, Pompeo released a statement calling on Riyadh to aid in a thorough investigation.

“We have seen conflicting reports on the safety and whereabouts of prominent Saudi journalist and Washington Post contributor Jamal Khashoggi,” Pompeo said. “As the President has conveyed, the United States is concerned by his disappearance. State Department senior officials have spoken with the Kingdom of Saudi Arabia through diplomatic channels about this matter.

“We call on the government of Saudi Arabia to support a thorough investigation of Mr. Khashoggi’s disappearance and to be transparent about the results of that investigation.”

Khashoggi disappeared after entering the Saudi Consulate in Istanbul on Oct. 2. Turkish officials have said they think that Khashoggi, a contributor to The Washington Post, was killed shortly after he arrived at the consulate to get paperwork for his upcoming marriage. Turkish authorities have not officially alleged that Khashoggi is dead, but Turkish President Recep Tayyip Erdogan said Sunday that the case was “very, very upsetting” and that he was “chasing” answers.

Saudi Arabia has denied harming Khashoggi.

According to two officials, senior members of the Trump administration have asked Riyadh to clarify the whereabouts of Khashoggi, a Saudi citizen who lived in the United States under self-imposed exile. His writings were frequently critical of the Saudi government and of Crown Prince Mohammed bin Salman, hailed by Trump as a reformer and a visionary.

The officials spoke on the condition of anonymity because they were not authorized to discuss the case on the record.

Pompeo tweeted Monday about his weekend trip to North Korea and Asian capitals, and congratulated his State Department team for “working hard to make progress on some of the world’s most pressing issues.”

Pompeo was asked about the case during a roundtable Monday in Seoul with the small group of journalists who traveled with him from Washington, but his spokeswoman interjected to say that he would address the question off the record. The State Department transcript of the session omitted that exchange.

There was no mention of Khashoggi in a State Department readout of an Oct. 3 call between Pompeo and the crown prince. At that point, Khashoggi had been reported missing by his Turkish fiancee, who said that she watched him enter the consulate but that he never exited. Three days later, Saturday, Turkish and U.S. officials said the Turks had concluded that Khashoggi was probably dead.

“The Secretary thanked the Crown Prince for his continued, strong partnership. The Secretary and the Crown Prince discussed a broad range of regional and bilateral issues, including Yemen and countering the Iranian regime’s malign activities in the region,” the statement said. “The Secretary and the Crown Prince also discussed areas for expanding U.S.-Saudi collaboration.”

Pompeo and Trump’s son-in-law and adviser, Jared Kushner, both have close relationships with the crown prince, frequently known by his initials, MBS. The young Saudi is a linchpin in the Trump administration’s efforts to isolate and economically squeeze Iran, and he would be a crucial backer for the still-secret administration plan for a peace settlement between Israel and the Palestinians.

But the crown prince is also seen as the main mover behind a diplomatic spat with Canada in August over what the Saudis claimed was inappropriate public criticism over human rights.

Saudi Arabia expelled the Canadian ambassador, yanked some investments and told Saudi students to leave their studies at Canadian universities.

“MBS is extremely sensitive around criticism and has been willing to react rashly to perceived slights against him,” said Ian Bremmer, founder of Eurasia Group, a political risk consultancy. He stressed that Khashoggi’s fate remains unknown.

“The more relevant point is that it’s hard to imagine President Trump wanting to make this into a significant issue,” Bremmer added, pointing to Trump’s dismissal last year of alleged Kremlin-directed killings of dissidents and journalists.

“There are a lot of killers. We have a lot of killers,” Trump said in a Fox News interview. “Well, you think our country is so innocent?”

Sen. Marco Rubio (R-Fla.) suggested in a tweet Sunday that he would seek to pressure or punish the Saudis if they were found responsible in Khashoggi’s death.

“If this deeply disturbing news report is confirmed, the United States & the civilized world must respond strongly, and I will review all options in Senate,” he wrote.

Aaron David Miller, a Middle East specialist at the Wilson Center who has worked in both Republican and Democratic administrations, said that Trump has “hung his hat in the region on the Saudis” and will be reluctant to criticize them.

“Likely Saudi involvement . . . should, but most likely will not, dissuade the Trump administration from pursuing a policy of placating and assuaging Riyadh,” said Miller, who is a friend of Khashoggi’s. “If the Saudis are in fact proven to have killed Khashoggi, upholding U.S. values and interests demand accountability, including use of sanctions or suspension of arms sales.”

Miller and others noted that the Trump administration imposed sanctions on Turkey in retaliation for the detention of American pastor Andrew Brunson. The administration is also harshly critical of human rights abuses in Iran, Cuba and Venezuela, but has eased its public criticism of North Korean abuses while negotiating over curtailing that country’s nuclear weapons program. Trump was also initially reluctant to blame Russia for the attempted murder of a former spy and his daughter in Britain this year.

“Had this been Bush 41 and James Baker, even with their ties to the Saudis, Baker would have called up somebody and said, ‘Look, we need to know now and we need to know exactly what your role is,’ ” Miller said, referring to former president George H.W. Bush and his secretary of state.

Ned Price, a national security spokesman for former president Barack Obama, said the Trump administration’s stance is unusual and troubling.

“Any other administration — whether mainstream Democratic or Republican — would be making the same position clear at this point: The onus is on the Saudis to prove Khashoggi left the consulate or is otherwise alive,” Price said. “What we’ve heard from this administration, however, is virtually nothing.”

Price said the Obama administration criticized Saudi Arabia in the case of a detained blogger, Raif Badawi.

“We made clear that his detention would be a major sticking point in the relationship. We’ve seen nothing of the sort from this administration, which claims that it finds private entreaties more persuasive,” Price said.

“The Trump administration has given carte blanche to the Saudis and has been at the beck and call of the crown prince. The Saudis may well have taken this kowtowing as a green light.”