Saudi Arabian leaders demonstrated a “serious commitment” to investigating the fate of a dissident journalist reportedly murdered by government officials, Secretary of State Mike Pompeo said following meetings with the royal family.

“My assessment from these meetings is that there is serious commitment to determine all the facts and ensure accountability, including accountability for Saudi Arabia’s senior leaders or senior officials,” Pompeo said Tuesday evening.

U.S.-Saudi relations entered an abrupt crisis in recent weeks, following the disappearance of Washington Post columnist Jamal Khashoggi. A critic of Crown Prince Mohammed bin Salman, Khashoggi has not been seen since he entered the Saudi consulate in Istanbul seeking marriage documents; he was reportedly murdered by a 15-person squad sent to Turkey for that purpose.

“[I]t is essential to determine what happened to Jamal Khashoggi,” Pompeo said. “During each of today’s meetings, the Saudi leadership strongly denied any knowledge of what took place in their consulate in Istanbul.”

The crown prince has been regarded as a potential reformer of Saudi Arabia’s theocratic society, with an additional willingness to form an Arab-Israeli partnership against Iran. Khashoggi’s disappearance threatens to create an historic rupture in an alliance of major significance for U.S. strategists, even those most alarmed by the rise of Saudi Arabia’s Persian rival for regional influence. Sen. Lindsey Graham, R-S.C., for instance, called Tuesday for the appointment of a new heir to the throne.

“This guy is a wrecking ball,” Graham said of the crown prince, known informally as MBS, on Fox News. “He had [Khashoggi] murdered in a consulate in Turkey and to expect me to ignore it, I feel used and abused. The MBS figure is to me toxic; he can never be a world leader on the world stage.”

That kind of response is commensurate with the scale of Saudi Arabia’s rogue actions, an expert critic of the regime suggested last week.

“Altering the relationship is making it unmistakably clear that we've lose confidence in Mohammed bin Salman,” former State Department negotiator Aaron David Miller, now the Middle East director at the Hudson Institute, told the Washington Examiner. “We don't want regime change, we don't want to create instability, but there may be internal consequences to what he's done. And while he's neutralized most of the power centers, there's one power center that he hasn't, and that's his father. He's not yet the king of Saudi Arabia.”

Pompeo met separately with King Salman and the crown prince on Tuesday. “We had direct and candid conversations,” he said. “I emphasized the importance of conducting a thorough, transparent, and timely investigation, and the Saudi leadership pledged to deliver precisely on that.”