That had led to greater confidence among some advisers that Saturday's dinner with Xi could produce a breakthrough, even though no official has been willing to explicitly say they expect the two men to come to an agreement. With nationalist sentiments rising in multiple countries, the G20 is being forced to questions how to deal with trade tensions that have caused disturbances in the global market.
"We hope the USA can show sincerity and meet China half way, to promote a proposal that both countries can accept", Foreign Ministry spokesman Geng Shuang told a briefing in Beijing. "We'll see", he said.
The president's economic adviser Larry Kudlow, in a briefing with reporters this week, similarly sought to make the case that the US comes into the negotiations from a stronger bargaining position than China.
G20 leaders including the presidents of the United States, Russia and China opened summit talks on Friday (Nov 30) stalked by the deepest divisions in the group's 10-year history.
The next G20 summit will be held in Osaka, Japan.
China is one of Buenos Aires' top trading partners and the main importer of Argentine agricultural commodities that are the backbone of its economy.
Joining other forecasters, economists at the Organization for Economic Co-operation and Development last week downgraded their outlook for global economic growth next year to 3.5 percent from a previous 3.7 percent.
Earlier in November, officials from countries attending a major Asia-Pacific summit failed to issue a joint statement for the first time after the USA delegation clashed with China over trade and security.
In Buenos Aires, Trump is also due to sit down with Putin for a bilateral meeting that has taken on added import after Russian Federation fired on and detained three Ukrainian ships in the Sea of Azov near Crimea.
The presidents of the United States and Russian Federation apparently haven't even said hello or shaken hands at the G20 summit, after their planned meeting was canceled.
The two leaders made headlines nonetheless through a hearty handshake ahead of the G20's family photo event.
The Kremlin said it had not been notified and only learned about it from the tweet.
Mr Putin's spokesman Dmitry Peskov reportedly greeted news of the cancellation by saying that while it was regrettable, it left the Russian president with a couple of extra hours to meet other leaders on the sidelines of the summit.
Trump, who has already slapped $250 billion in tariffs on China, sounded upbeat about making progress with his counterpart Xi Jinping after weeks of dire warnings.
Putin grinned broadly and welcomed Saudi Crown Prince Mohammed bin Salman like a long-lost friend with a high-five ahead of a group photo where Trump stood grimly.
White House Press Secretary Sarah Huckabee Sanders said that Presidents Donald Trump and Mauricio Macri met Friday and "reiterated their shared commitment" to face challenges including "predatory Chinese economic activity".
Macron and British Prime Minister Theresa May both said they were raising the killing of Khashoggi during meetings with the 33-year-old prince.
The de facto Saudi leader denies having prior knowledge of Khashoggi's killing at the Saudi consulate in Istanbul in October. "That's all I said". However, it is being reported that Ms Merkel still plans to have her one-on-one with Mr Putin, with the pair set to meet on Saturday morning.
If Ukraine was the stated reason to cancel his talks with Putin, the latest revelations in the probe showed that Trump can not escape the lengthening shadow of what he again called the "witch hunt" at home when he comes to worldwide fora like the G20.