The G20 summit kicked off on Friday in Buenos Aires with Saudi Crown Prince Mohammed bin Salman facing an awkward reception from world leaders.

As dignitaries drifted in at the summit's start, French President Emmanuel Macron was filmed having a tense conversation with the Saudi leader.

In the video, which was shared widely on social media, the two are seen speaking in English.

Much of the audio is inaudible. However, it is possible to make out bin Salman saying "Don't worry," to which Macron responds "I am worried".  Later, Macron says: "You never listen to me," and bin Salman replies: "I will listen, of course."

At the end of the exchange, Macron is heard saying: "I'm a man of my word."

Later, the crown prince, known as MBS, found himself sidelined during the official "family photo" of leaders, standing at the far edge of the portrait, largely ignored. Once the photo was taken he quickly exited the stage without shaking hands or talking with the other leaders.

Bin Salman is under intense scrutiny after a team of 15 Saudis murdered journalist Jamal Khashoggi in his country's consulate in Istanbul on 2 October. The crown prince denies involvement, yet the CIA has reportedly concluded that he ordered the assassination.

The murder has also led to heightened criticism of MBS and his country's role in the war in Yemen.

A French presidential spokesperson said Macron told bin Salman at the summit that Europeans will insist on international experts being part of the investigations into the Saudi journalist's murder.

In a five-minute exchange on the summit's sidelines, Macron conveyed "very firm" messages to the prince over the murder of Khashoggi and on the need to find a political solution for the situation in Yemen, the official said.

Macron also discussed oil prices with MBS, and the role Riyadh can play in their fluctuation, the French presidential office said.

The Saudi leader appeared to have no such awkwardness with Russian President Vladimir Putin, however.

The two were seen clasping hands and smiling as they greeted one another.

Russia has not criticised Saudi Arabia or MBS over Khashoggi's killing, as Putin said in October that he lacked information about the matter and would not tear up Moscow's relations with Riyadh because of it.

A senior White House official said US President Donald Trump and MBS "exchanged pleasantries" at the G20 leaders' session.

Asked later by reporters what the two leaders discussed, Trump said they "had no discussion".

"We had no discussion. We might, but we had none," Trump said, as reported by the White House press office.

Meanwhile, the Saudi Ministry of Foreign Affairs shared images on Twitter of MBS meeting with Mexican President Enrique Pena Nieto and South Korean President Moon Jae-in on the sidelines of the summit.

It also said the crown prince met with South Africa's president, Cyril Ramaphosa, and Chinese President Xi Jinping on the sidelines of the conference.

In another tweet, the ministry hailed MBS has been the "youngest leader in the G20 summit of a leading economic power".