Already the French Presidency has said that Emmanuel Macron spoke to the Crown Prince on the summit's sidelines about both the journalist's murder and Saudi's role in the war in Yemen, which the United Nations has called the world's worst humanitarian crisis.
France also imposed sanctions, including travel bans, on 18 Saudi citizens linked to the murder.
Prince Mohammed also met Chinese president Xi Jinping on the summit sidelines, the Saudi Press Agency said on Twitter.
Despite the reassurances, Macron appears to reply "I am anxious", as the awkward encounter continued.
Turkey's Recep Tayyip Erdogan, who has been sharply critical of Saudi Arabia over the incident, is also in attendance.
The two sides reviewed the available opportunities to export the Saudi non-oil products to India, and ways to develop bilateral trade through sustainable arrangements, especially in strategic commodities such as Saudi fertilizers as well as promoting the exchange of investment in the industrial sector, it said.
The comment was made in a tweet attached to a video of the Russian and Saudi leaders greeting each other warmly at the G20 summit in Argentina with an enthusiastic high-five that turned into an emphatic handshake.
Saudi Arabia maintains that the Crown Prince had no knowledge of the killing.
However, a White House official said the U.S. president had so far only exchanged pleasantries with him.
Bin Salman told Macron not to worry, but Macron replied, "I am anxious".
It's possible to make out Prince Mohammed saying "Don't worry", to which the French President responds "I am worried".
Saudi-owned TV station Al Arabiya said there had been a friendly meeting between Donald Trump and the crown prince.
MBS is expected to meet with just a few leaders at the summit in Buenos Aires, including Putin.
Missing entirely was Chancellor Angela Merkel, whose arrival was delayed for the better part of a day by a serious technical failure on her plane, which forced her to return to Germany Thursday night.