Mnuchin played down the meeting to reporters saying it was "not a negotiating meeting", and said the USA would continue to press tariffs on China unless the country intends to "come back to the table and negotiate".
Mnuchin said Saturday that he would hold routine talks on various issues and then meet privately with Yi Gang, chairman of the People's Bank of China.
The Trump administration is taking steps to impose 25 per cent tariffs on the remaining US$300 billion worth of Chinese imports so far untouched by the trade war between the world's two largest economies.
Men: Dark Phoenix: Every Easter Egg and Reference
This is the story of one of the X-Men's most beloved characters, Jean Grey, as she evolves into the iconic DARK PHOENIX . We made a decision to take a look back at the reviews for all 12 movies in the cinematic universe of X-Men.
"We have to hurry up", stressed French Finance Minister Bruno Le Maire during a panel discussion of top policymakers before the G20 meeting officially opened. Those tactics, the USA contends, include hacking into US companies' computers to steal trade secrets, forcing foreign companies to hand over sensitive technology in exchange for access to the Chinese market and unfairly subsidizing Chinese tech firms.
The other topic dominating the G20 finance ministers' meeting is the impact of spiraling global trade conflicts on an increasingly fragile economic outlook.
He has, however, downplayed the significance of the meeting, . saying it won't be a negotiating session.
The IMF has said US-China tariffs could shave global GDP by 0.5 percent in 2020 or about US$455 billion, stressing the need to resolve the differences to avoid plunging the world economy into another crisis.
"Although I don't like them, I do appreciate the impetus for these issues", added the top USA finance official.
Pomp, parade marks Queen Elizabeth II's official birthday
It started out as a traditional preparation for battle, whereas nowadays it's just a bit of a jolly day out. Meghan took a break from maternity leave to join the royal family for the annual trooping the colour .
America's huge trade deficit with China - a record $379 billion previous year - is one factor driving Trump's frustrations with Beijing. They did not refer directly to the tariffs war between the United States and China, though leaders participating in the meetings indicated it was the No. 1 concern.
"If we can get the right agreement, that's great". Beijing also blamed the USA for the trade war and accused Washington of being an untrustworthy negotiator while threatening to cut off the supply of rare earth minerals that are widely used in electric cars and mobile phones.
China has blamed the USA for the breakdown and vowed to reciprocate for the increased tariffs in various ways. The meeting comes just weeks before world leaders, including President Trump and Chinese President Xi Jinping, head to Osaka, Japan, for the G-20 summit.
The representatives from Japan, US, China, France and the United Kingdom supported modifying their current regulations that allow digital giants such as Amazon, Google and Facebook to be taxed where they are headquartered, and instead implement taxes based on their revenue and number of users in every market where they operate.
There was no immediate word from the Chinese side about the meeting between Yi and Mnuchin. "If they don't, we'll proceed with our tariffs".
French Open glance: Nadal aims for 12th title against Thiem
Thiem's coach Nicolas Massu asked tournament officials on Saturday to move the finals to Monday, but had his request denied. I'm sure Rafa when he woke up in the morning, he was like, 'Oh yay, that's going to be a good day in the office'".
The new U.S. -Mexico-Canada deal has been heading toward a vote in Congress and might have been stymied by new tariffs.