Nikki Haley warns China on trade with North Korea if it wants U.S. trade UNITED NATIONS (AP) — U.S. Ambassador Nikki Haley warned China on Wednesday that it risks its massive trade with the United States if its business with North Korea violates U.N. sanctions. In a hard-hitting speech at an emergency meeting of the U.N. Security Council following Pyongyang's successful launch of an intercontinental ballistic missile, she said that "the world has become a more dangerous place" and China has a key role in promoting peace and "preventing a catastrophe."