Ford Motor said strong trade partnerships are needed to maintain the company’s U.S. exports that have grown 50 percent since 2009, when auto-industry sales reached a 27-year low.

Ford, the second-biggest U.S. automaker, is the nation’s largest exporter of vehicles, Joe Hinrichs, Ford’s president of the Americas, said at the Chicago Auto Show.

While Ford shipped more than 370,000 vehicles out of the U.S. last year, and more than 30,000 Edge and Explorer sport-utility vehicles produced in North America were sold to customers in China, automakers will have to adapt as the gaps in labor, material and energy costs narrow between the world’s two biggest vehicle markets, he said.

“One of the big questions that manufacturers are trying to answer right now is whether growth can be sustained both in the U.S. and in China as these two key markets begin to look more alike,” Hinrichs said.

“What do we need to change if the U.S. and China are going to avoid repeating the sins of previous growth cycles ― when overcapacity and the loss of cost competitiveness doomed the automotive industry to long down cycles?”

Trade agreements, such as the Trans-Pacific Partnership, or TPP, that prevent currency manipulation, which he called “the major barrier of the 21st century,” are a crucial step.

“TPP is not likely to generate any net benefits for American manufacturers if it does not address the critical issue of currency manipulation,” Hinrichs said.

U.S. automakers, led by Dearborn, Michigan-based Ford, have accused Japan of weakening the value of the yen to benefit its auto industry. Japan denies manipulating its rates.

“The real elephant in the room right now is currency manipulation and we need to make sure that it is not ignored,” he said. (Bloomberg)