U.S. Secretary of State Mike Pompeo says Saudi Arabia told him their investigation into the disappearance and alleged killing of Saudi writer Jamal Khashoggi won't spare anyone, including royals.

Pompeo told journalists Wednesday morning before flying to Turkey that the kingdom promised a "transparent investigation."

Pompeo said: "They made a commitment to hold anyone connected to any wrongdoing that may be found accountable for that, whether they are a senior officer or official."

U.S. Secretary of State Mike Pompeo, center, walks to a plane before leaving Riyadh, Saudi Arabia Wednesday, Oct. 17, 2018. (Leah MillisPool Photo via AP)

U.S. Secretary of State Mike Pompeo, center, walks to a plane before leaving Riyadh, Saudi Arabia Wednesday, Oct. 17, 2018. (Leah MillisPool Photo via AP)

Asked if that would include members of the royal family, America's top diplomat said: "They made no exceptions on who they would hold accountable."

Khashoggi vanished Oct. 2 on a visit to the Saudi Consulate in Istanbul. Turkish officials say Saudi officials killed and dismembered The Washington Post columnist.

U.S. Secretary of State Mike Pompeo, center right, shakes hands with a Saudi official before leaving Riyadh, Saudi Arabia Wednesday, Oct. 17, 2018. (Leah MillisPool Photo via AP)

U.S. Secretary of State Mike Pompeo, center right, shakes hands with a Saudi official before leaving Riyadh, Saudi Arabia Wednesday, Oct. 17, 2018. (Leah MillisPool Photo via AP)