"It's moving very very slowly - so slowly that I think we will have to stay in this room past midnight, again", an Asian delegate who was attending the closed-door discussion told Reuters.
The president has pledged to reduce America's trade deficit by pursuing new trade agreements with countries he argues are engaging in unfair trade policies, especially China.
Trump has threatened to raise the existing 10% tariff on $250 Billion of imported Chinese goods to 25% in January if the countries fail to end the dispute with the threat of new tariffs on an additional $267 billion of goods not now subject to tariffs.
U.S. President Donald Trump said Thursday a trade deal with Beijing was "close" but added he might prefer not to reach one, cooling hopes for a breakthrough at a summit this week.
"We're going to be talking about lots of good things for Argentina, for the United States, including trade, including military purchases, and other things".
In such a scenario, China has threatened to retaliate in kind, placing levies on all goods imported from the US.
Markets are hoping a deal can be reached before the end of the year, when USA duty rates are due to increase significantly.
In recent months the United States and China have been engaged in rather heated negotiations regarding worldwide trade deals, and the U.S. has leveraged tariffs in an attempt to gain the upper hand.
As the leaders arrived, Argentine security forces began locking down the central business district in Buenos Aires on Thursday.
An expected high-profile bilateral meeting between Trump and Russia's Vladimir Putin planned for Saturday was abruptly canceled by Trump in a tweet citing Russia's seizure of Ukrainian vessels over the weekend.
Posing for photos in a gilded salon, Trump spoke about their longtime personal relationship and said they would discuss trade, military purchases and other issues.
"The summit seems a nonsense to me", call center worker Agustina Vianello, 25, told AFP.
"His message should be that everybody who wants to invest must come to South Africa and it is a safe place to invest".
When President Donald Trump travels overseas, he increasingly likes to keep it quick.
The U.S., Canada and Mexico are expected to sign the new United States-Mexico-Canada Agreement that is replacing NAFTA during a ceremony Friday.
"However, it should be feasible for some kind of agreement to be reached to prevent the dispute worsening if both sides are reasonable", it said.
All eyes will be on Trump and and Chinese President Xi Jinping as clouds gather over the global economy.