BEIJING (AP) — China's government says it has filed a challenge to a U.S. tariff hike on solar panels in the World Trade Organization, adding to its sprawling trade dispute with President Donald Trump.

The Commerce Ministry said Wednesday the 30 percent tariffs announced in January violate WTO rules and improperly help U.S. producers.

The Trump administration previously defended the tariffs on solar cells and modules as being in line with WTO rules. It said they were necessary to shield American manufacturers that were hurt by a flood of imports supported by subsidies and other improper measures.

The two governments have raised tariffs on billions of dollars of each other's goods. The next round of increases threatened by both sides is due to take effect next week.