Many US lawmakers have called for US weapons sales to be cut off in response to Mr Khashoggi's murder inside the Saudi consulate in Istanbul, a step Mr Trump has rejected.
Saudi Arabia sent a toxicologist and a chemicals expert to Istanbul to cover up the murder of journalist Jamal Khashoggi before the Turkish police searched the kingdom's consulate, a senior Turkish official said on Monday.
The Saudi officials tried to rip out a camera inside the Istanbul consulate on October 2, the day Khashoggi disappeared, and days later tampered with cameras at a police security booth in the building, Al-Jazeera reported, citing Turkish media.
It was unclear whether Prince Mohammed will accompany him for the remainder of the tour, which comes as Saudi Arabia faces global outrage over Khashoggi's murder on October 2 in its consulate in Istanbul.
No trace of Khashoggi's remains has turned up, even as the 59-year-old journalist's sons appealed on the US television news network CNN on Sunday for the Saudis to return his body so he can be buried in the major Islamic pilgrimage city of Medina with the rest of his family.More news: Sheriff: 10-year-old says she stomped head of baby in panic
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Salah Khashoggi, who lives in Saudi Arabia, became the public face of the family's sorrow when a photograph of him, stone-faced, meeting Saudi King Salman and Crown Prince Mohammed bin Salman was shared on social media and interpreted as evidence of the family's rage at the royal family.
In Qassim, the king will launch health, education, and infrastructure projects as well as check on "the conditions of citizens and get acquainted with their needs", the Saudi Gazette newspaper said.
But in fact, Salah Khashoggi said, the king had assured him that "everybody involved will be brought to justice" for the killing.
The two men were part of a team of Saudi investigators who spent several days in Turkey visiting the consulate and the consul's residence, ostensibly to help with the investigation into Khashoggi's disappearance, the newspaper reported.
Saudi Arabia acknowledged last month that Turkish evidence indicates that the Khashoggi's killing at the consulate was premeditated, shifting its explanation in an apparent effort to ease worldwide outrage over the death. "I think my statement was very clear", Aiban said.
The Saudi prosecutor-general has acknowledged that the murder was premediated. The Saudis have until Friday to report back on whether they will accept any of the recommendations. It has observer status, having quit the 47-member forum in June accusing it of bias against Israel.