China’s Foreign Ministry said on Tuesday it has lodged representations with the United States over Washington’s plan to end waivers for Iranian oil imports. “The decision from the U.S. will contribute to volatility in the Middle East and in the international energy market,” ministry spokesman Geng Shuang told a news briefing. Washington has announced that all Iran sanction waivers will end by May, sending crude oil prices higher and pressuring importers to stop buying from Tehran.