The meeting of 20 finance ministers from the world's largest economies ended after two days with no agreement supporting the group's decade-old tradition of promoting free trade and rejecting protectionism.
The annual meeting of G20 finance ministers ended Saturday in Germany without a concrete agreement on free trade after the USA blocked any language that encouraged past commitments on the open flow of goods and services.
"We believe in free trade, we are in one of the largest markets in the world, we are one of the largest trading partners in the world, trade has been good for us, it has been good for other people", Mnuchin said.
Mnuchin and Chinese Finance Minister Xiao Jie and central bank Gov. Zhou Xiaochuan are scheduled to hold a bilateral meeting in Baden-Baden, one of the G-20 officials said.
Mnuchin said the U.S. would work with worldwide partners but review trade deals that disadvantage the U.S.: "It's free trade, balanced trade and fair trade". Their stance on issues such as free trade and climate change have major implications on the global economy. We do not want unfair competition.
Since President Donald Trump has taken office, he has been vocal in pursuing an "America First" policy and has warned firms would face "consequences" if they moved business operations overseas.
The treasury secretary made it clear that the Trump administration planned to press on with its plans to review market regulations as well as the size of the USA trade deficit compared with the record trade surplus run up by nations such as Germany.
The G20 has in the past pledged support to the existing multilateral trade system, including the World Trade Organisation (WTO).
"I understand what the president's desire is and his policies and I negotiated them from here, and we couldn't be happier with the outcome", he said.
Wolfgang Schaeuble, the finance minister of host country Germany, argued that it was not true that officials failed to find common ground.
Conspicuous by its absence was the phrase "we will resist all forms of protectionism" that was contained in the communique from the last meeting of the group in China, July 2016.
He also rejected a description of his policies as "isolationist".
Advocates for free trade such as the International Monetary Fund say trade restrictions will only hurt growth and won't benefit ordinary people, while urging measures to spread the benefits of trade more widely. "But it wasn't clear what one or another meant by that".
The G20 is an informal forum on economic cooperation made up of 19 countries plus the European Union.