U.S Treasury Secretary Steven Mnuchin appears in front of the Senate Appropriations Subcommittee hearing on proposed budget estimates and justification for FY2018 for the Treasury Department on Capitol Hill in Washington, U.S. July 26, 2017. REUTERS/Eric Thayer

WASHINGTON (Reuters) - U.S. Treasury Secretary Steven Mnuchin said on Thursday the Trump administration may seek a provision to deter currency manipulation in the North American Free Trade Agreement as part of its planning for future free trade deals.

Mnuchin, testifying before the House Financial Services Committee, said that currency manipulation by U.S. trading partners needs to be met with an impact, “and not just talk.”

He said that a proposal from the Peterson Institute for International Economics for the Treasury to engage in countervailing currency interventions -- essentially buying the currency of a country that is deliberately trying to suppress it -- could be one of many such possibilities. But Mnuchin added that the scale of such operations could be prohibitively large.