A man uses phone under a Volkswagen logo at the Shanghai Auto Show, in Shanghai, China April 20, 2017. REUTERS/Aly Song

BEIJING (Reuters) - Volkswagen AG's VOWG_p.DE chief executive Herbert Diess said on Tuesday that a Chinese tariff hike on U.S vehicle imports would be tough for the firm, amid a brewing trade war and threats of punitive tariffs exchanged between Washington and Beijing.

Diess, speaking ahead of the Beijing autoshow, said that the German car maker also had no plans to alter its current joint venture partnerships in China, the world’s largest auto market, after the country said it would loosen ownership rules.