EU Council President Donald Tusk called on fellow leaders to discuss "trade wars, the tragic situation in Syria and Yemen and Russian aggression in Ukraine".
The incident has caused countries to re-examine their relationship with Saudi Arabia, and USA lawmakers are reconsidering whether Washington should support the Saudi war against Yemen.
Khashoggi's killing has put mounting pressure on Riyadh and MBS, who Turkish officials - and reportedly the Central Intelligence Agency - have concluded was behind the critic's death.
The crown prince's father, King Salman, has publicly backed MBS over recent weeks, and the royal family appears to have publicly accepted that MBS and his succession can not be challenged without seriously disrupting the internal stability of the family and, by extension, the state.
Theresa May has vowed to be "robust" as she meets Saudi Arabia's leader to press him over the murder of journalist Jamal Khashoggi.
"Noting the steps taken by the Saudi investigation since the Foreign Secretary had met with the crown prince and King Salman on 12 November, she encouraged the crown prince to ensure that Saudi Arabia co-operated fully with the Turkish authorities and worked to bring both investigations to an acceptable close".
In a video shared to Twitter via the Saudi Gazette, an irritated Macron is seen grumbling to the Crown Prince: "You never listen to me".
The murder of Khashoggi has caused widespread backlash against the Saudi regime, which had recently enjoyed an exceptionally friendly relationship with countries like the USA and France.
"To me, we've got a relationship with a country that's a semi-important country and a semi-important ally".
Western nations are also calling for an end to the Saudi-led military campaign in neighbouring Yemen, which was launched by Prince Mohammed, as a humanitarian crisis there worsens.
"The world is a very unsafe place!" the statement began.
The report said it was unclear in the excerpts if the comments came directly from the crown prince or were from someone describing the communications.
Trump has since voiced sadness over the killing of Khashoggi, who lived in the United States and wrote for The Washington Post.
But the Turkish leader, also attending the G20, was visibly cooler toward the 33-year-old prince and on Saturday directly criticized him for the first time over the killing of Khashoggi, a royal confidant turned critic. I continue to work on this issue.