RNA - The Guardian reported on Friday, citing unnamed sources, Pompeo has privately raised concerns about MbS's contact with Saud al-Qahtani, who is accused of masterminding Khashoggi's murder.
Khashoggi was killed in early October 2018, after entering the Saudi consulate in Istanbul to obtain documents for his upcoming marriage. After initially offering several contradictory statements, the Saudi kingdom confirmed the journalist was killed inside Riyadh consulate in Turkey. US intelligence agencies have reportedly concluded that MbS was involved in Khashoggi's killing - a conclusion the kingdom denies.
Al-Qahtani is believed to have played a pivotal role in Khashoggi's assassination by first trying to lure him back to Saudi Arabia. He met the Saudi hit team before they left for Turkey and allegedly gave orders to kill Khashoggi if he refused to return to his country voluntarily.
Al-Qahtani was dismissed as a royal adviser following Khashoggi's murder, but the ambiguity surrounding his status has raised questions about whether he continues to have influence behind the scenes.
In January, The Washington Post reported that MbS remained in regular contact and continued to seek advice from al-Qahtani.
The WaPo quoted a Saudi source as saying that al-Qahtani had recently made two trips to the United Arab Emirates (UAE), even though he was presumed to be under house arrest in Riyadh.
The adviser also reportedly met senior deputies from the royal court's Centre for Studies and Media Affairs recently at his home in Riyadh and told them that he had been blamed and "used as a scapegoat". Al-Qahtani had run the centre until shortly after Khashoggi's death.
The Guardian also reported that al-Qahtani is still active within MbS's private office.
The State Department told The Guardian it would not discuss private diplomatic conversations.
The Guardian's report comes against the backdrop of increased pressure on Pompeo and the White House to do more to hold Saudi Arabia accountable for Khashoggi's death.
Congress has sent a bill to President Donald Trump that would end US support for the Saudi-UAE war in Yemen. The legislation is seen as a strong rebuke over Trump's support for Saudi Arabia in the wake of Khashoggi's murder. Trump has not acted on the measure, but the White House has previously indicated that the president will veto the bill.
Last week, the State Department barred entry to 16 Saudi nationals, including al-Qahtani, over what it described as their role in the murder of Khashoggi.
The section under which the individuals have been designated "provides that, in cases where the Secretary of State has credible information that officials of foreign governments have been involved in significant corruption or gross violations of human rights, those individuals and their immediate family members are ineligible for entry into the United States".
The State Department previously revoked visas of nearly two dozen Saudi officials and froze the assets of 17 others.