Speaking on the sidelines of a meeting in Hawaii where ministers are negotiating a 12-nation trade deal, Robb said member countries of the Trans-Pacific Partnership (TTP) were considering a U.S. proposal for a separate forum.
The United States had not suggested including currency rules in the TTP deal, he said. U.S. officials have warned such rules could undermine the independence of monetary policy and other TPP partners, including Japan, are also opposed to the idea.
"It's a forum of finance ministers who will agree to consider on a regular basis aspects of currency manipulation," he said in an interview.
"They are not looking to put it in as part of the TPP treaty, they are looking ... to make use of the relationship of the 12 countries to consider currency issues on an ongoing basis, so we hopefully don't see the re-emergence of currency manipulation."
The move would stop short of calls by U.S. automakers such as Ford Motor Co and some U.S. lawmakers to include sanctions against currency manipulation in the trade deal.
Weaker exchange rates make a country's exports cheaper and give exporters a competitive advantage.
"We certainly know that this is a major issue of concern to the U.S. Congress so given the importance of the United States we will always listen carefully to any U.S. proposals," he told Reuters. "I think we will find a way through this."
Japanese Economy Minister Akira Amari said currency concerns should not be addressed in the TPP. "I think foreign exchange is an issue which the International Monetary Fund and currency authorities should discuss," he said, when asked for Japan's view on the proposal.
U.S. officials were not immediately available to comment.