Transportation Secretary Sean Duffy has sharply criticized Ford Motor Company over its business relationships with Chinese companies, warning that they create national-security concerns for the United States.

Duffy specifically objected to Ford’s use of technology from Chinese battery maker CATL at its Michigan battery plant and its partnership with Chinese automaker Geely in Europe.

He also criticized Ford for continuing to manufacture Lincoln vehicles in China for the U.S. market until 2030, arguing that this leaves the company dependent on Chinese manufacturing while American workers miss out on those jobs.

Ford strongly rejected Duffy’s criticism, saying the letter was a “wrongheaded attempt to capture headlines” and emphasizing that it owns and operates its Michigan battery plant and employs the American workforce there, CNBC has reported.

The dispute comes as Washington considers tougher restrictions on Chinese automakers and technology, while the Trump administration increases pressure on American companies to reduce their dependence on China.