The trade conflict between the world's two largest economies has seen a 6 percent slump in the onshore yuan against the greenback this year, raising speculation that China has deliberately weakened its currency and drawing Trump's ire.
Trump is unhappy with the WTO's failure to hold Beijing to account for failing to open its economy as envisioned when China joined the WTO in 2001.
"I think we're very close to doing something with China, but I don't know that I want to do it because what we have right now is billions and billions of dollars coming into the United States in the form of tariffs or taxes".
It added that market participants were "intensely focused on the leaders' meeting as a potential inflection point in the escalating economic tensions" between the USA and China.
They also scaled back their expectations, cutting out mention of rising protectionism mainly aimed at Trump.
An EU official said the language now being negotiated for the final statement of the G20 would also support reform of the multilateral trade body needed to improve its function.
Despite Trump's dismissal of concerns about global warming, China, France and the United Nations came together Friday to pledge their support for the Paris climate accord.
"The fact that the G-20 is taking place in South America for the first time is nearly beside the point", Shifter said.
On migration, the US negotiator said too much talk about migration would have been a "deal-breaker" for Trump, the European officials said. So they came up with "minimalist" language that acknowledges growing migrant flows and the importance of shared efforts to support refugees and solve the problems that drive them to flee.
They also protested against the amount spent on the summit at a time when Argentina is in an economic crisis and against President Mauricio Macri's policies to combat inflation.
"There were moments when we thought all was lost", one European official said, "moments when we spent two hours on one sentence".
German Chancellor Angela Merkel blamed the crisis "entirely" on Russian Federation and said she would raise the issue with Mr Putin.
"We will send a clear signal - in any case, most of us" - for the success of global climate talks starting in Poland on Sunday, Ms Merkel added.
Mr Macri said the matter of the killing would be "on the table" during bilateral and possibly broader meetings.
Russian media are now reporting that the two will have a brief and impromptu meeting on the sidelines of the summit, contrary to Mr Trump's earlier position that he didn't want to meet because of Russia's seizure of three Ukrainian navy vessels last week.
The agreement was reached before Trump's highly anticipated dinner with Chinese President Xi Jinping, slated for later Saturday.
China responded with its own tariffs on $110 billion in U.S. goods. "If they are able to begin to agree, it would be a good signal that would reduce the impacts on global commerce".
A summit of the world's top economies will open on Friday with leaders struggling over fallout from a US-China trade war that has roiled global markets and bracing for the kind of divisive geopolitical drama that President Donald Trump often brings to the worldwide stage.
There was an implicit contrast in some of the tributes offered at the Buenos Aires summit between Bush and the current White House occupant, Donald Trump, whose disruptive brand of diplomacy has stoked the deepest divisions in the G20´s 10-year history.
"We have agreed on a statement that reflects the necessity of revitalizing trade, of revitalizing the WTO".
"The president is the one that took that leap and that's what has us very alarmed on that side of the industry", he said during on Thursday.
On the eve of the summit, G20 nations were still trying to reach consensus on wording for the summit's communique on major issues including trade, migration and climate change, which in past years have been worked out well in advance.