STRESA, Italy (Reuters) - U.S. Treasury Secretary Janet Yellen said on Thursday that G7 finance ministers will discuss their concerns about China's excess industrial capacity and potential responses, adding that without policy changes in Beijing their economies will be hit with a flood of cheap Chinese goods.

"This week will be a key opportunity to discuss how China's macroeconomic imbalances and industrial overcapacity can affect our economies," Yellen told a news conference ahead of a Group of Seven finance meeting in Stresa, Italy.

"We'll also discuss our responses and the approaches that we're taking to raise these concerns directly with China.

Yellen called earlier this week for the U.S. and Europe to respond to China's overinvestment in electric vehicles, solar products, semiconductors, steel and other key sectors in a "strategic and united way" to keep manufacturers viable on both sides of the Atlantic.

(Reporting by David Lawder; Editing by Keith Weir)