In recent months, the world's two largest economies have impose punitive tariffs on billions of dollars of one another's goods.
With the United States and China locked in growing disputes over commerce and security that have raised questions about the future of their relationship, Trump and Xi are due to sit down for dinner at the end of a two-day gathering of world leaders in Buenos Aires.
Washington is scheduled to raise import tariffs on US$200 billion worth of Chinese products from 10 per cent to 25 per cent from January 2019 if it can not come to terms with Beijing.
A Chinese foreign ministry official in Buenos Aires said there were signs of increasing consensus ahead of the discussions, although differences remained, Reuters reported.
"All issues being discussed at the summit have the same relevance", he told reporters.
Yet, underlining that the new deal may not be quite the game-changer he professes, the signing will be executed by senior trade negotiators from the three countries rather than their leaders attending the G20. I think we'd like to.
China said Thursday that tariffs on US autos would be 15 percent if not for the trade dispute, and it called for a negotiated solution. "Way, way, way above my pay grade", he said.
Trump met briefly with the crown prince, with the two men reportedly exchanging pleasantries during a leaders' session, a White House official said.
As a result of the U.S.' decision to levy a 27.5-percent tariff on Chinese cars imported to the U.S., China now charges a 40-percent tariff on American cars exported to the Asian country.
However, delegates to the Buenos Aires talks said good progress had been made on economic sections of the final communique.
Michael Shifter, head of the Inter-American Dialogue, a Washington-based think tank, said that this G-20 summit was once considered an opportunity for Latin American members Argentina, Brazil and Mexico "to project a regional bloc to shape a global agenda".
Melania Trump skips unveiling of White House Christmas decorations
The sunny hallway is lined with two columns of pine trees that are solid red and lack decorations. They include an ornament emblazoned with the slogan for her child well-being campaign, Be Best.
Highlighting the deep rifts within the G20, European Council President Donald Tusk said the European Union would extend its economic sanctions on Moscow in December, after Russian ships fired on Ukrainian vessels in the Sea of Azov last week, seizing the boats and sailors.
Russian Federation and Ukraine have traded blame over the weekend ship incident - which Mr Trump cited as a reason for cancelling a much-anticipated meeting with Mr Putin at the G20.
But on the eve of what is seen as the most important meeting of United States and Chinese leaders in years, both sides said differences remained, and the outcome of the talks were uncertain.
On Friday, a USA official said progress was being made on the joint statement and the White House was "optimistic" about the document as a whole.
The Saudi leader has been the subject of widespread condemnation after Washington Post journalist Jamal Khashoggi was killed during a visit to the Saudi Arabian consulate in Turkey in October. Human Rights Watch asked Argentine prosecutors to investigate him for human rights abuses.
British Prime Minister Theresa May, speaking to Sky News before the summit, said she would press the crown prince both on Yemen and Khashoggi at the G20.
Saudi Arabia has denied that bin Salman played a role, but US intelligence agencies concluded he ordered the killing.
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.
Trump's remarks came as he prepared to depart for the summit.
Their embrace comes amid reports that Russian Federation and Saudi Arabia have reached a pact to cut oil production when the OPEC cartel meets on December 6 in Vienna, to help shore up collapsing crude prices.