China has filed a lawsuit with the World Trade Organization's (WTO) dispute settlement mechanism following the United States decision to raise the "reciprocal tariffs" on Chinese imports from 34 percent to 84 percent, a spokesperson for China's Ministry of Commerce said on Wednesday.The United States tariff move gravely violates WTO rules, and the additional 50 percent tariff compounds its mistake and further exposes its nature of unilateral bullying, the spokesperson added.China will resolutely safeguard its legitimate rights and interests in accordance with WTO rules and defend the multilateral trading system and the international economic and trade order.