Yellen says she won't rule out possible tariffs on China's green exports

U.S. Treasury Secretary Janet Yellen on Monday said she would not rule out any measures, including potential tariffs, on China's green energy exports.

"I wouldn't rule out anything out at this point. We need to keep everything on the table. We want to work with the Chinese to see if we can find a solution," she said in an interview with CNBC's Sara Eisen, when asking about the possibility of Washington imposing tariffs if China does not adjust its approach to industry incentives.

"I'm not thinking so much of export restrictions, as some shifts in their macroeconomic policy, and a reduction in the amount of, particularly local government subsidies, to firms," Yellen said.

She nevertheless stressed the need to create a level playing field in the green technology space.

"We just want to make sure that we're not driven out of business, and that our firms and workers have opportunities in these industries which will be important ones in our future," she added.

Yellen is currently in Beijing and is due to leave China on Tuesday. She arrived in Guangzhou on Thursday last week to connect with Chinese officials as fractious economic relations between the two countries continue.

The U.S. has been increasingly voicing concerns about an oversupply of subsidised Chinese clean energy products to international markets, which it says harms the competitiveness of domestic firms That anxiety is shared by U.S. allies including Japan and Europe, as a glut of cheap Chinese products, such as solar panels, have flooded their markets.

"It's fine for China's firms to export in this industry, to develop it. But some of the techniques that they use — subsidizing their firms very heavily and then supporting them even when they're losing money ...