The United States Treasury chief Janet Yellen has warned that China's subsidies for industry could pose a risk to global economic resilience.

Yellen made this known during a visit to China on Friday, as she arrived in the southern city of Guangzhou on Thursday for several days of talks with Chinese officials, which is her second visit to the world's second-largest economy in less than a year.

She expressed concerns about China's "overcapacity" undercutting American and other countries' companies.

She told a gathering of the US business community in Guangzhou on Friday that direct and indirect government support was leading to production capacity, which she claims exceeds China's domestic demand, as well as what the global market can bear.

Yellen also told the gathering, organised by the US Chamber of Commerce in China, that she would seek to raise with Chinese officials the "challenges" faced by US businesses operating in the country.

There are reports that Chinese subsidies to industries, such as solar, electric vehicles and batteries, risk creating a surplus of cheap goods that threatens those sectors elsewhere.