Lawmakers want to know more information regarding Ford’s EV battery deal with China’s CATL amid increasing tensions between the two countries.

China remains one of the globe’s biggest sources of elements necessary for EV battery production. Not surprisingly, Ford struck a deal with CATL to produce such batteries. Give the state of affairs between the US and China, however, US lawmakers want to know more about the licensing deal between the two companies.

“While we are encouraged to see Ford take a small first step in reevaluating its deal with CATL, we are concerned that Ford has not been fully transparent with our requests for documents and information,” according to the letter that was sent to Ford and shared with TechCrunch.

It is believed that increased scrutiny from lawmakers may have been a motivation behind Ford’s decision to pause work on its $3.5 billion Michigan EV battery plant. Ford planned on using CATL’s battery in that plant.