G20 leaders pose for a family photo during the G20 summit in Buenos Aires, Argentina November 30, 2018.
To be sure Putin's exuberant greeting of the prince was seen as over the top and promptly went viral.
The CIA has rated its assessment that Mohammed was involved in the killing at "medium-to-high confidence", and privately, officials have said it is inconceivable that the prince, who exercises total authority over the government, could not have known about such an audacious operation.
But senators have voiced outrage over attacks on civilian targets, including hospitals and a school bus, as well as a Saudi hit squad's murder in October of journalist Jamal Khashoggi inside the kingdom's Istanbul consulate.
Turkey's President Recep Tayyip Erdogan has demanded that Saudi Arabia extradite the suspects in writer Jamal Khashoggi's murder.
The crown prince told his advisers "we could possibly lure him outside Saudi Arabia and make arrangements" if Khashoggi, who was previously based in Virginia, did not return to Saudi Arabia.
Trudeau said he told Putin of the need to release imprisoned Ukrainian sailors during a meeting of world leaders on Friday, but there wasn't an opportunity for Putin to respond to the remarks. May said she called for a full, credible and transparent investigation, while Macron insisted the crown prince allow global investigators to take part in any inquiry.
Earlier in November, the Wall Street Journal said that excerpts of the assessment it had not previously reported state that the Central Intelligence Agency has "medium-to-high confidence" that Prince Mohammed "personally targeted" Khashoggi and "probably ordered his death" - but added: "To be clear, we lack direct reporting of the Crown Prince issuing a kill order".
US Secretary of State Mike Pompeo acknowledges that the humanitarian crisis in Yemen - where millions are at risk of starvation - has reached "epic proportions" but says Washington and Riyadh are offering aid.
On Friday, Mrs May delivered a "robust" message to Saudi Crown Prince Mohammed bin Salman that the United Kingdom expected his country to co-operate fully with the Turkish probe and to conduct its own investigation in a "credible and transparent" way.
The crown prince also discussed investments and economic partnerships with Indian Prime Minister Narendra Modi and Chinese President Xi Jinping. "We believe bringing to light all aspects of the murder and prosecution of all perpetrators will be in the interest of Saudi Arabia", he said.
Argentina's President Mauricio Macri and his wife Juliana Awada who is of Lebanese and Syrian descent, hosted world leaders for a gala dinner and a theatrical performance at Teatro Colon.
In the end, they were not.
The federal prosecutor's office assigned to review the case had not announced whether a formal investigation would be opened by the close of the summit on Saturday.