G20 leaders opened annual talks on Friday stalked by the deepest divisions since their first summit 10 years ago, with US President Donald Trump under fire for destroying the group's past consensus on trade and climate change.
G20 stands for "Group of 20".
So far, the United States has imposed tariffs on $250 billion of Chinese imports - or about half the goods it imports from China each year - in response to Beijing's alleged theft of intellectual property and technology, as well as other trade complaints.
The summit marks a quick return to the worldwide stage for the Prince Mohammed after the kingdom came under fire for the killing of journalist Jamal Khashoggi in its Istanbul consulate.
Meanwhile the US, Canada and Mexico are expected on Friday to sign a revamped version of the North American trade pact NAFTA, which Trump excoriated when running for president.
Mr Trump is also not meeting privately in Buenos Aires with the crown prince, who is trying to rebuild his image after the killing of Washington Post columnist and royal family critic Jamal Khashoggi inside the Saudi consulate in Istanbul.
The key issue there will be the nations' trade tariffs dispute.
United Nations chief Antonio Guterres said in Buenos Aires that "this is a make-it-or-break-it moment" on the issue.
Russian Federation and Ukraine have traded blame over the weekend ship incident - which Trump cited in canceling a much-awaited meeting with Putin at the G-20.
French President Emmanuel Macron held a five-minute exchange with the crown prince during which, a French official said, Mr Macron had conveyed "very firm" messages over the Khashoggi affair.
Tough talking is expected at the summit, especially between Trump and Xi Jinping of China, over global trade.
In a pre-G20 report, the International Monetary Fund said the auto tariffs could cut three-fourths of a percent off the global economy.
Like Trump and Xi, Prime Minister Theresa May will arrive in Buenos Aires late on Thursday to bring another intriguing subplot to the world's pre-eminent economic forum.
Canadian Prime Minister Justin Trudeau called on Trump to remove tariffs on steel and aluminum, saying they remain a major economic obstacle.
A giant blimp of a baby Donald Trump made the president feel very "unwelcome" when he came to London in July, he said.
However, Mrs Merkel's own arrival at the summit has been delayed by a technical fault in her plane.
Regarding Mrs May's visit, he said: 'Dialogue must be maintained'.
"We are not withdrawing our historic claim", he added.
Who are the G20 countries? "The focus of this opportunity is in the reestablishment of trust". "Several marched topless with colorful national flags of summit countries painted on their chests".
Argentina has deployed around 25,000 police officers and soldiers to prevent violence similar to that seen during last year's G20 summit in Hamburg, Germany, when hundreds of police officers were injured.
Argentina's constitution recognizes universal jurisdiction for war crimes and torture, allowing courts to investigate and prosecute such crimes regardless of where they were committed and the nationality of the suspects or victims.
30 November 2018
30 November 2018
27 November 2018
27 November 2018
27 November 2018
26 November 2018
28 November 2018
26 November 2018
26 November 2018
28 November 2018
28 November 2018
28 November 2018