Japan urged China on Tuesday to alter trade practices that it considers unfair, such as imposing tariffs on auto parts that are as high as those on assembled cars, and expanding its list of hazardous chemicals on short notice to effectively block exports of items that contain them.

The government's 2006 Report on the WTO Inconsistency of Trade Policies by Major Trading Partners points out 27 Chinese trade practices considered problematic, including enforcement of antidumping measures and failure to crack down on pirated and counterfeit items.

Japan has requested that China lower to 10 percent its planned 25 percent tariff on auto parts, scheduled to take effect in July, if the value of imported auto parts exceeds 60 percent of the assembled vehicle's price. The 25 percent tariff is the same as that levied on finished cars.