Warren Maruyama focuses his international trade practice on assisting clients in dealing with cutting-edge trade policy challenges, including the Trump administration's efforts to renegotiate the North American Free Trade Agreement (NAFTA) and negotiate bilateral trade agreements and its threats to impose higher duties on U.S. companies and U.S. trading partners under Sections 301, 232, and 201 of U.S. trade law. He advises U.S. and multinational firms on the use of U.S. trade policy and trade law mechanisms and World Trade Organization (WTO) disputes.

Drawing on his senior-level experience at the Office of the United States Trade Representative (USTR), the White House, and the U.S. International Trade Commission, Warren has advised clients regarding many free trade agreements (FTAs), including NAFTA, Trans-Pacific Partnership (TPP), Transatlantic Trade and Investment Partnership (TTIP), Brexit, and China's WTO accession. He has also advised clients on U.S. FTAs involving Korea, Colombia, Peru, Panama, and Australia.

Warren is recognized for his strategic vision and ability to develop innovative, cutting-edge solutions to the trade challenges facing clients. From 2007- 2009, he served as USTR general counsel, overseeing the filing of 10 U.S. WTO and bilateral challenges to foreign trade barriers; Doha Round and FTA negotiations; the development of Section 301 retaliation lists; and the USTR's roles in the U.S.-China Strategic Economic Dialogue and Joint Commission on Commerce and Trade. He helped negotiate the so-called "May 10" agreement between the Bush administration and House Democrats, which resolved a decade-long impasse over the role of labor and environmental rules in U.S. FTAs.