U.S. Treasury Secretary Janet Yellen said on Thursday that it was important for G7 countries and other economies to show China that it faces a "wall of opposition" over its excess industrial capacity, which threatens a flood of cheap exports.

Yellen told a news conference ahead of a Group of Seven finance ministers meeting in northern Italy that concerns expressed by Washington and European capitals about China's overinvestment in electric vehicles, solar products, semiconductors and other strategic sectors were shared by emerging market economies including Mexico, India and South Africa.

(Reporting by David Lawder Editing by Keith Weir)