The U.S. and China are locked in negotiations over curbing North Korea’s energy trade in response to its fifth nuclear test last month, according to four diplomats from United Nations Security Council countries with direct knowledge of the talks. The world’s two biggest economies — both of whom can veto any resolution — are discussing restrictions on North Korea’s trade in coal, iron ore and crude oil, according to the diplomats, who asked not to be named because the discussions are private. Other nations also considering separate sanctions against North Korea once the Security Council acts, the diplomats said. The U.S. and its allies are seeking to further tighten sanctions against Kim Jong Un’s regime to prod him into abandoning a pursuit of nuclear weapons that has only intensified […]