The presidents of China and Iran are among world leaders addressing a United Nations summit Saturday after the gathering unanimously approved an ambitious blueprint to tackle more than a dozen major global issues. Goals of the 15-year road map endorsed Friday by the U.N’s 193 members include eradicating extreme poverty and fighting climate change. The new goals are expected to cost between $3.5 trillion and $5 trillion every year until 2030. How to implement them is expected to dominate the three-day summit. After speeches by presidents Xi Jinping of China and Hassan Rouhani of Iran on Saturday, President Barack Obama and the leaders of Britain and France will address the meeting on its last day Sunday.