Yellen told members of the Senate Finance Committee that said she would be focused on making sure that sanctions were used "strategically and appropriately."

Asked if she would repudiate unilateral protectionism, Yellen said she believed the best way to address unfair trade practices was to work with allies, and to focus directly on abuses such as theft of intellectual property and unfair subsidies.

(Reporting by Andrea Shalal and David Lawder; Editing by Chizu Nomiyama)