US President Barack Obama has filed a trade complaint against China, accusing it of illegally subsidising exports of cars and car parts.
A White House official said China's actions were forcing US manufacturers to shift production overseas.
The key principle at stake is that China must play by the rules of the global trading system, said a White House official.
Mr Obama's move is seen as political.
He is expected to discuss the World Trade Organization (WTO) action against China on Monday as he visits the US state of Ohio, which has more than 50,000 workers employed in the car industry.
'Harming workers'
In excerpts of a speech released by the Obama campaign, the president is expected to say: Today, my administration is launching new action against China - this one against illegal subsidies that encourage companies to ship auto-parts manufacturing jobs overseas.
Those subsidies directly harm working men and women on the assembly line in Ohio and Michigan and across the Midwest. It's not right; it's against the rules; and we will not let it stand.
Ohio is a critical state in the 6 November presidential elections, with success there seen as crucial to becoming president.
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