"The historical language was not relevant," he told journalists after the gathering of finance ministers and central bankers in Baden Baden, western Germany.
"What is relevant is what we agreed as a group: to strengthen the contributions of trade to our economies and we will strive to reduce excess global imbalances to promote inclusiveness and fairness and reduce inequality."
"I think that accurately reflects what we as a group talked about."
The G20 has in the past pledged support to the existing multilateral trade system, including the World Trade Organisation (WTO).
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But Mnuchin suggested that the US may in future look to renegotiate long-standing deals, including those agreed within the framework of the WTO.
"We want to reexamine certain agreements, we have talked about reexamining NAFTA," he told journalists, referring to the North American Free Trade Agreement between Canada, Mexico and the United States.
He also dismissed concerns that the communique did not reaffirm G20 members' commitment to the 2015 Paris climate accords, saying it did not fall under his remit as treasury secretary.
"That's more of an issue for G20 leaders" when they meet in Hamburg in July, he said.